The New World Leaf-Nosed Bat Radiation

I’ve said a few times here at TetZoo that bats have never really been given adequate coverage. This isn’t because I’m not interested in them: on the contrary, I think about bats more than I think about most other groups of mammals, and I see them and watch them more often than I do most other mammal groups. For a group that includes about 18% of extant mammalian species (using 2019 figures*), I can’t pretend to have ever given bats fair coverage. Having said all that, bats have actually been covered at TetZoo a fair bit: there was an entire 20-part series on vesper bats (properly Vespertilionidae) at ver 3, and I also published several ver 2 articles on the history and evolution of vampire bats, and on much else besides. The fact that all of these articles have been rendered worthless via the removal of their images is mightily dispiriting though, and essentially means that I need to start from scratch.

* c 6495 mammal species, c 1200 bat species.

TetZoo Towers bat library. The several boxfiles of reprints and photocopied articles are not shown. Image: Darren Naish.

TetZoo Towers bat library. The several boxfiles of reprints and photocopied articles are not shown. Image: Darren Naish.

Here, I want to talk about a group I don’t think I’ve ever covered at TetZoo before, namely the phyllostomids, or New World leaf-nosed bats, American leaf-nosed bats or spear-nosed bats. This is a large, American group that contains around 200 living species, making it the third largest bat family (vesper bats are the biggest group, followed by fruit bats). The group has sometimes been called Phyllostomatidae – the vernacular version of which is phyllostomatid – but this is less popular than Phyllostomidae. I have no idea which is really correct here and opt to merely follow majority usage on these sorts of things (insert quote from Gene Gaffney**). It’s not strictly true that I’ve never covered phyllostomids before, since vampires – once upon a time given their own eponymous family (Desmodontidae) – are now universally agreed to be nested within Phyllostomidae, and I have at least written about them.

Chrotopterus , a big spear-nosed bat. Notice how this bat has relatively broad, low-aspect wings and a large, deep uropatagium (the membrane between the legs). Contrast this with some of the images below. Image: George Henry Ford, public domain (original   here  ).

Chrotopterus, a big spear-nosed bat. Notice how this bat has relatively broad, low-aspect wings and a large, deep uropatagium (the membrane between the legs). Contrast this with some of the images below. Image: George Henry Ford, public domain (original here).

Phyllostomids occur from Argentina in the south to the southern USA (Nevada being their most northerly occurrence) in the north, and they’re highly diverse ecologically and behaviourally. They include insectivores, frugivores, nectarivores, palynivores (that’s pollen-eaters), omnivores, animalivores and (of course) obligate sanguivores. Numerous different taxonomic subdivisions have been named. We don’t need to worry about any of this in detail but, in simplified terms, Macrotinae (big-eared bats), Micronycterinae (little big-eared bats) and Desmodontinae (vampires) are outside a much larger clade that includes Vampyrinae (false vampires and kin) and Phyllostominae (spear-nosed bats and kin) as well as the nectarivorous and frugivorous Glossophaginae (long-tongued and long-nosed bats) and Stenodermatinae (American fruit bats, fig-eating bats and kin) (Baker et al. 1989, 2003, 2012; but see Wetterer et al. 2000). Vampyrinae is a clade within Phyllostominae according to some studies, in which case it gets down-graded to Vampyrini (Baker et al. 2003). All of this is depicted in a cladogram below.

Some phyllostomid portraits. At left: Big-eared woolly bat or Peters’s false vampire  Chrotopterus auritus . At right: Hairy big-eyed bat  Chiroderma villosum . Images: both Guilherme Garbino, wikipedia, CC BY-SA 4.0 (originals   here   and   here  ).

Some phyllostomid portraits. At left: Big-eared woolly bat or Peters’s false vampire Chrotopterus auritus. At right: Hairy big-eyed bat Chiroderma villosum. Images: both Guilherme Garbino, wikipedia, CC BY-SA 4.0 (originals here and here).

Phyllostomids are mostly brownish bats with simple, narrow ears. A nose-leaf – typically simple and spear-shaped – is common but not present in all species, a tragus is always present, and many (but not all) of the species that lack nose-leaves have chin-leaves (or a series of chin ‘warts’) instead. Facial stripes are common, dark dorsal stripes are present in a few species, and such things as white patches at the wing tips and yellow rims to the ears and nose-leaves are present in some (Hill & Smith 1984). The tail is variously long, or short, and even absent altogether in some taxa, and similar variation is present in the uropatagium, or tail membrane.

The tail and uropatagia (the membranes joining the inner sides of the legs to the tail) are reduced, and sometimes highly reduced, in some phyllostomids. Here, we see this reduced condition in (at left) the Toltect fruit-eating bat  Dermanura tolteca  and (at right) in a Little yellow-shouldered bat  Sturnira lilium . Images: M.H. de Saussure, 1860, in public domain (original   here  ); Tobusaru, wikipedia CC BY 3.0 (original   here  ).

The tail and uropatagia (the membranes joining the inner sides of the legs to the tail) are reduced, and sometimes highly reduced, in some phyllostomids. Here, we see this reduced condition in (at left) the Toltect fruit-eating bat Dermanura tolteca and (at right) in a Little yellow-shouldered bat Sturnira lilium. Images: M.H. de Saussure, 1860, in public domain (original here); Tobusaru, wikipedia CC BY 3.0 (original here).

Skeletally, phyllostomids are robust, have a distinctive humerus where the distal end is angled relative to the shaft, and have a prominent secondary articulation between the large bony lump (properly termed the greater tuberosity) at the proximal end of the humerus and the scapula (Czaplewski et al. 2007). That’s right: a number of bat groups have an accessory peg-in-socket articulation involving the humerus and the body of the scapula. This means that the humerus and scapula are locked together during the upper part of the wing stroke (Hill & Smith 1984).

The most prominent exception to the ‘phyllostomids are mostly brown’ generalisation is the Honduran white bat  Ectophylla alba , sometimes likened to a fuzzy ping-pong ball and well known for its habit of constructing tents by biting through leaf ribs such that the two sides of the leaf droop on either side of the central axis. Note the yellow ears and nose leaf! The individual at left is releasing a bit of urine. Images:   Geoff Gallice  , wikipedia, CC BY 2.0 (original   here  );   Leyo  , wikipedia, CC BY-SA 2.5. (original   here  )

The most prominent exception to the ‘phyllostomids are mostly brown’ generalisation is the Honduran white bat Ectophylla alba, sometimes likened to a fuzzy ping-pong ball and well known for its habit of constructing tents by biting through leaf ribs such that the two sides of the leaf droop on either side of the central axis. Note the yellow ears and nose leaf! The individual at left is releasing a bit of urine. Images: Geoff Gallice, wikipedia, CC BY 2.0 (original here); Leyo, wikipedia, CC BY-SA 2.5. (original here)

Some phyllostomids are really exceptional as goes their anatomical and behavioural novelty. Perhaps the most remarkable are the long-tongued glossophagine flower bats, some of which have extraordinary tubular snouts, remarkably long tongues tipped with papillae, and a highly reduced dentition. The most extreme example of this sort of thing is the Banana bat, Trumpet-nosed bat or Colima long-nosed bat Musonycteris harrisoni of Mexico, an ‘extreme’ mammal as goes snout length. It’s fairly typical for people who aren’t that familiar with bat diversity to confuse glossophagines with the Old World flower-feeding megabats grouped together in Macroglossinae. There’s obviously a degree of evolutionary convergence here, though it hasn’t been that well explored in the literature, to my knowledge. Various glossophagines have symbiotic relationships with sympatric plants. Incidentally, Pallas’s long-tongued bat Glossophaga soricina is able to see UV light (Winter et al. 2003).

Some distantly related (but broadly similar) members of the phyllostomid clade Glossophaginae. At left: a long-tongued champion (though not necessarily the longest-tongued of phyllostomids), Pallas’s long-tongued bat  Glossophaga soricina . At right: Underwood’s long-tongued bat  Hylonycteris underwoodii . Images: Betty Wills, wikipedia CC BY-SA 4.0 (original   here  ); Karin Schneeberger/  Felineora  , wikipedia CC BY-SA 3.0 (original   here  ).

Some distantly related (but broadly similar) members of the phyllostomid clade Glossophaginae. At left: a long-tongued champion (though not necessarily the longest-tongued of phyllostomids), Pallas’s long-tongued bat Glossophaga soricina. At right: Underwood’s long-tongued bat Hylonycteris underwoodii. Images: Betty Wills, wikipedia CC BY-SA 4.0 (original here); Karin Schneeberger/Felineora, wikipedia CC BY-SA 3.0 (original here).

Entirely different specialisations are seen in the short-faced, frugivorous phyllostomids included within Stenodermatinae. These have flattened, broad teeth, typically have white facial stripes (an aposematic warning of their powerful bites?), and are sometimes handsome or even cute, big-eyed bats. One of the strangest of bats – the Wrinkle-faced or Lattice-winged bat Centurio senex – belongs to this group. The naked, wrinkled faces of males are mostly concealed by massive skin flaps when the bat is roosting or sleeping. There are also neck glands that seem to secrete scent, and obvious transverse bands on the wing membranes.

Resting Wrinkle-faced bats  Centurio senex  partially conceal their faces beneath thick skin folds. Translucent patches on the lower of these skin folds seem to allow these bats to detect light-level changes even when their faces are covered. Image: Jplevraud, wikipedia CC BY-SA 3.0 (original   here  ).

Resting Wrinkle-faced bats Centurio senex partially conceal their faces beneath thick skin folds. Translucent patches on the lower of these skin folds seem to allow these bats to detect light-level changes even when their faces are covered. Image: Jplevraud, wikipedia CC BY-SA 3.0 (original here).

 My favourite phyllostomids are very different from tubular-snouted flower-feeders and short-face fruit-eaters: they are the robust, more generalised species traditionally lumped together in Phyllostominae (though the name Vampyrinae has also been used for some of them). These are mostly omnivores that eat insects, fruit and small vertebrates, and some are specialised predator bats that variously catch and eat amphibians, mammals (including other bats) and birds. They include Peters’s woolly false vampire Chrotopterus auritus, the Frog-eating bat Trachops cirrhosus – famous for eating frogs and selecting them on the basis of their calls – and the spectacular Linnaeus’s false vampire Vampyrum spectrum, a predatory giant that can, in cases, have a wingspan of over 1 meter.

Vampyrum , the False vampire or Spectral bat (see comments for a hot take on the term ‘false vampire’), has to be considered one of the most awesome of all bats. It’s convergently similar to the distantly related megadermatid bats of Africa, Asia and Australasia, also (confusingly) often called false vampires. Image: Marco Tschapka, wikipedia, CC BY-SA 3.0 (original   here  ).

Vampyrum, the False vampire or Spectral bat (see comments for a hot take on the term ‘false vampire’), has to be considered one of the most awesome of all bats. It’s convergently similar to the distantly related megadermatid bats of Africa, Asia and Australasia, also (confusingly) often called false vampires. Image: Marco Tschapka, wikipedia, CC BY-SA 3.0 (original here).

The very impressive skull of  Vampyrum . It is robust, with big, strong teeth, especially prominent upper canines (which have an additional internal cusp) and a prominent sagittal crest. The skull can be 5.1 cm long in total (which is big for a bat). Image: Naturalis Biodiversity Center, wikipedia, public domain (original   here  ).

The very impressive skull of Vampyrum. It is robust, with big, strong teeth, especially prominent upper canines (which have an additional internal cusp) and a prominent sagittal crest. The skull can be 5.1 cm long in total (which is big for a bat). Image: Naturalis Biodiversity Center, wikipedia, public domain (original here).

When this variation in feeding ecology is mapped onto a phylogeny, it would appear that the earliest phyllostomids were insectivorous, that omnivory, nectarivory (or nectivory, take your pick) and palynivory evolved from among these insectivores, and that frugivores evolved from among nectarivores and palynivores (Baker et al. 2012). The highly specialised vampires appear – according to phylogenetic data – to have evolved directly from insectivores (which is a surprise in view of some models proposed to explain vampire evolution) and at least some members of the main frugivorous clade appear to have reverted to insectivory (Baker et al. 2012; but see Wetterer et al. 2000). Of the various evolutionary events that must have occurred here, it’s the transition to obligate frugivory that seems to have been the most successful, since the frugivorous clade is the largest (as in, most species-rich) within Phyllostomidae, containing about 70 species in 20 genera.

A few more vertebrate-eating phyllostomids. At left: California leaf-nosed bat  Macrotus californicus , the most northerly occurring phyllostomid. At right: Fringe-lipped bat  Trachops cirrhosus , a widespread species of Central and South America that eats seeds, fruits, arthropods and lizards in addition to frogs. Images: National Wildlife Service, wikipedia, public domain (original   here  ); Karin Schneeberger/  Felineora  , wikipedia CC BY 3.0 (original   here  ).

A few more vertebrate-eating phyllostomids. At left: California leaf-nosed bat Macrotus californicus, the most northerly occurring phyllostomid. At right: Fringe-lipped bat Trachops cirrhosus, a widespread species of Central and South America that eats seeds, fruits, arthropods and lizards in addition to frogs. Images: National Wildlife Service, wikipedia, public domain (original here); Karin Schneeberger/Felineora, wikipedia CC BY 3.0 (original here).

This is also the radiation that’s seemingly resulted in the greatest, most rapidly evolved amount of morphological variation, since everything here seems to have happened within the last 10 million years and has given rise to taxa that are among the most divergent and specialised of phyllostomids. Also of interest here is that some lineages within this frugivorous clade appear to have evolved in the Antilles before invading the mainland (Dávalos 2007), a case of ‘upstream colonisation’ that contradicts traditional scenarios whereby continental animals give rise (via ‘downstream colonisation’) to island-dwelling forms.

Substantially simplified phyllostomid cladogram, based mostly on Baker  et al . (2003), and using their nomenclature (though they regarded false vampires - as Vampyrini - as nested within Phyllostominae). Images (top to bottom):  Macrotus  = National Wildlife Service, wikipedia, public domain (original   here  );  Desmodus  = Uwe Schmidt, wikipedia, CC BY-SA 4.0 (original   here  );  Vampyrum  = Marco Tschapka, wikipedia, CC BY-SA 3.0 (original   here  );  Phyllostomus  = Karin Schneeberger/  Felineora  , wikipedia, CC BY 3.0 (original   here  );  Platalina  = Juan A. Malo de Molina, wikipedia, CC BY-SA 3.0 (original   here  );  Sturnira  = Burtonlim, wikipedia, CC BY-SA 3.0 (original   here  ).

Substantially simplified phyllostomid cladogram, based mostly on Baker et al. (2003), and using their nomenclature (though they regarded false vampires - as Vampyrini - as nested within Phyllostominae). Images (top to bottom): Macrotus = National Wildlife Service, wikipedia, public domain (original here); Desmodus = Uwe Schmidt, wikipedia, CC BY-SA 4.0 (original here); Vampyrum = Marco Tschapka, wikipedia, CC BY-SA 3.0 (original here); Phyllostomus = Karin Schneeberger/Felineora, wikipedia, CC BY 3.0 (original here); Platalina = Juan A. Malo de Molina, wikipedia, CC BY-SA 3.0 (original here); Sturnira = Burtonlim, wikipedia, CC BY-SA 3.0 (original here).

Where in the bat tree? What sort of bats are phyllostomids, and what do we know about their evolutionary history? On the basis of anatomical characters, bat experts have generally thought that phyllostomids are close allies of naked-backed, moustached or ghost-faced bats (Mormoopidae) and bulldog bats and kin (Noctilionidae), the whole lot being grouped together in a clade termed either Phyllostomatoidea or Noctilionoidea (and it’s the last of those terms that should be preferred, so I understand). In turn, this group was thought – again, on the basis of anatomical characters – to be closely related both to vesper bats and their kin (Vespertilionoidea), and to a clade that includes both sheath-tailed bats and kin (Emballonuroidea) and horseshoe bats and kin (Rhinolophoidea) (Smith 1976).

Prior to recent (post-2000-ish) molecular studies, noctilionoids were thought to be close kin of rhinolophoids as well as emballonuroids and vespertilionoids. Rhinolophoids are now known to belong elsewhere. The illustrations here are among the many, many bat drawings I’ve done for my in-prep textbook project,   progress on which can be seen here.   Image: Darren Naish.

Prior to recent (post-2000-ish) molecular studies, noctilionoids were thought to be close kin of rhinolophoids as well as emballonuroids and vespertilionoids. Rhinolophoids are now known to belong elsewhere. The illustrations here are among the many, many bat drawings I’ve done for my in-prep textbook project, progress on which can be seen here. Image: Darren Naish.

Molecular studies, mostly published since 2000, have substantially revised our view of the bat family tree, however, and it’s now clear that rhinolophoids are not close to the other groups listed here at all (they are, instead, close relatives of megabats). Noctilionoids are still close kin of vespertilionoids, however. It also now seems that Mystacinidae and Myzopodidae are part of Noctilionoidea (Jones et al. 2002, 2005, Teeling et al. 2005, 2012). I’ll be talking more about ideas on bat phylogeny in a future article.

Simplified cladogram depicting the affinities of several of the bat groups shown - via morphological and molecular studies - to belong together within Noctilionoidea. The illustrations here are among the many, many bat drawings I’ve done for my in-prep textbook project,   progress on which can be seen here.   The  Vampyrum  representing Phyllostomidae, incidentally, is a placeholder which needs replacing (the existing illustration was copied directly from the work of another artist). Image: Darren Naish.

Simplified cladogram depicting the affinities of several of the bat groups shown - via morphological and molecular studies - to belong together within Noctilionoidea. The illustrations here are among the many, many bat drawings I’ve done for my in-prep textbook project, progress on which can be seen here. The Vampyrum representing Phyllostomidae, incidentally, is a placeholder which needs replacing (the existing illustration was copied directly from the work of another artist). Image: Darren Naish.

What does the fossil record say about phyllostomid history? The pre-Pleistocene phyllostomid record is not great but it’s still at least good enough to show that the extinct phyllostomids of the Miocene – most notably those from La Venta in Colombia – were superficially much like living ones, and that the extinct species concerned were doing the sorts of things that phyllostomids do today. The group had almost certainly, therefore, undergone its main flowering and diversification by around 20 million year ago. The Pleistocene phyllostomid record, in contrast, is good and numerous extant taxa are known from sediments of this age. 

Beautiful illustration of Salvin’s big-eyed bat  Chiroderma salvini , a stenodermatine phyllostomid that has a wide range across South and Central America. The facial stripes are not normally this pronounced in life, though it should be noted that populations are variable as goes stripe thickness. Image: Joseph Smit, in public domain (original   here  ).

Beautiful illustration of Salvin’s big-eyed bat Chiroderma salvini, a stenodermatine phyllostomid that has a wide range across South and Central America. The facial stripes are not normally this pronounced in life, though it should be noted that populations are variable as goes stripe thickness. Image: Joseph Smit, in public domain (original here).

And that’s where we’ll end things for now. I’d like to say a lot more about these bats, so we’ll be returning to them in time. And in fact I need to say a lot more about bats in general, so stay tuned for that too.

If you enjoyed this article and want to see me do more, more often, please consider supporting me at patreon. The more funding I receive, the more time I’m able to devote to producing material for TetZoo and the more productive I can be on those long-overdue book projects. Thanks!

For previous TetZoo articles on bats (concentrating here on articles that haven’t been stripped of images, as is the case for all ver 2 articles and the vast majority of ver 3 articles)…

Refs - -

Baker, R. J., Bininda-Emonds, O. R. P., Mantilla-Meluk, H., Porter, C. A. & Van Den Bussche, R. A. 2012. Molecular time scale of diversification of feeding strategy and morphology in New World leaf-nosed bats (Phyllostomidae): a phylogenetic perspective. In Gunnell, G. & Simmons, N. (eds). Evolutionary History of Bats: Fossils, Molecules and Morphology. Cambridge University Press, Cambridge, pp. 385-409.

Baker, R. J., Hoofer, S. R., Porter, C. A. & Van Den Bussche, R. A. 2003. Diversification among New World leaf-nosed bats: An evolutionary hypothesis and classification inferred from digenomic congruence of DNA sequence. Occasional Papers, Museum of Texas Tech University 230, 1-32.

Baker, R. J., Hood, C. S. & Honeycutt, R. L. 1989. Phylogenetic relationships and classification of the higher categories of the New World bat family Phyllostomidae. Systematic Zoology 38, 228-238.

Czaplewski, N. J. 1997. Chiroptera. In Kay, R. F., Madden, R. H., Cifelli, R. L. & Flynn, J. J. (eds) Vertebrate Paleontology in the Neotropics: The Miocene Fauna of La Venta, Colombia. Smithsonian Institution Press (Washington and London), pp. 410-431.

Dávalos, L. M. 2007. Short-faced bats (Phyllostomidae: Stenodermatinae): a Caribbean radiation of strict frugivores. Journal of Biogeography 34, 364-375.

Hill, J. E. & Smith, J. D. 1984. Bats: A Natural History. British Museum (Natural History), London.

Jones, K. E., Bininda-Emonds, O. R. P. & Gittleman, J. L. 2005. Bats, clocks, and rocks: diversification patterns in Chiroptera. Evolution 59, 2243-2255.

Jones, K. E., Purvis, A., MacLarnon, A., Bininda-Emonds, O. R. P. & Simmons, N. B. 2002. A phylogenetic supertree of the bats (Mammalia: Chiroptera). Biological Reviews 77, 223-259.

Smith, J. D. 1976. Chiropteran Evolution. Texas Tech University, Lubbock.

Teeling, E. C., Dool, S. & Springer, M. S. 2012. Phylogenies, fossils and functional genes: the evolution of echolocation in bats. In Gunnell, G. & Simmons, N. (eds). Evolutionary History of Bats: Fossils, Molecules and Morphology. Cambridge University Press, Cambridge, pp. 1-22.

Teeling, E. C., Springer, M. S., Madsen, O., Bates, P., O’Brien, P. & Murphy, W. J. 2005. A molecular phylogeny for bats illuminates biogeography and the fossil record. Science 307, 580-584.

Wetterer, A. L., Rockman, M. V. & Simmons, N. B. 2000. Phylogeny of phyllostomid bats (Mammalia: Chiroptera) data from diverse morphological systems, sex chromosomes, and restriction sites. Bulletin of the American Museum of Natural History 248, 1-200.

Winter, Y., López, J. & von Helversen, O. 2003. Ultraviolet vision in a bat. Nature 425, 612-614.

** In a technical article on fossil side-necked turtles, Gaffney said of a very similar nomenclatural disagreement: “it’s true, I don’t give a rat’s ass which is used”.

New Living Animals We Want to Find

As a regular denizen of the TetZooniverse, you may well remember the July 2017 article ‘Fossils We Want to Find’ in which I discussed a list of hypothetical fossil things that we might one day discover but haven’t yet. Wouldn’t it be fun to do the same sort of thing with extant species; that is, with discoveries pertaining to living, breathing animals? Over at the Zoology for Enthusiasts facebook group (a spinoff of the Tetrapod Zoology facebook group), Jordan Fryer suggested doing exactly this, and consequently people have been coming up with their own suggested living animals that might await discovery. Because this seemed like a lot of fun (and a chance to discuss some really neat and unusual stuff), I thought I’d give it a go.

The 2017 precursor to the article you’re reading here was all about fossil animals. It included this photo, which shows me in the act of discovering a dinosaur bone in the Moroccan Sahara. Image: Richard Hing.

The 2017 precursor to the article you’re reading here was all about fossil animals. It included this photo, which shows me in the act of discovering a dinosaur bone in the Moroccan Sahara. Image: Richard Hing.

Naturally, any list of this sort is horribly subjective, reflecting the interests and biases of the person compiling the list, but so be it. It also seems all too easy to turn any compilation into a ‘list of most discoverable cryptids’: for those of you who don’t know, I have a long-standing interest in cryptozoology and have published on it quite frequently (see Naish (2017) for starters). For the most part, I’ve not done this, though read on.

Many of my thoughts on mystery animals can be found in my   2017 book  Hunting Monsters   . I am not - sorry - much impressed by the case for such supposed animals as the mokele-mbembe, an artistic reconstruction of which is shown at right. Image: David Miller, in   Mackal (1987)  .

Many of my thoughts on mystery animals can be found in my 2017 book Hunting Monsters. I am not - sorry - much impressed by the case for such supposed animals as the mokele-mbembe, an artistic reconstruction of which is shown at right. Image: David Miller, in Mackal (1987).

I’ve also mostly excluded hypothetical discoveries that are inspired by the creatures of cryptozoology but could arguably be considered independent of the cryptozoological literature. In part this is because I don’t think they’re plausible or worth considering, but it’s also because they’re cliched and the opposite of original. So, no ‘living sauropods from the Congo’ or ‘living plesiosaurs in Loch Ness’, for example.

As for what I have selected: well, some of my suggestions are sillier than others, and some are perhaps not that interesting to non-specialists. But, whatever. Feel free to dissect my suggestions in the comments, and perhaps come up with your own.

Among my suggested ‘fossils we want to find’ are protobats (like the hypothetical examples shown at left, from Graham (2002)) and a good skeleton of the giant hominid  Gigantopithecus blacki . This ilustration of a lower jaw is from Simons & Ettel's (1970) magazine article. Images: Graham (2002), Simons & Ettel (1970).

Among my suggested ‘fossils we want to find’ are protobats (like the hypothetical examples shown at left, from Graham (2002)) and a good skeleton of the giant hominid Gigantopithecus blacki. This ilustration of a lower jaw is from Simons & Ettel's (1970) magazine article. Images: Graham (2002), Simons & Ettel (1970).

A habitually bipedal, large, non-human hominid. Whatever you think of all those stories, anecdotes and sightings about bigfoot, yeti, almas, orang-pendek, yowie and so on and on, the fact remains that the discovery of a large, bipedal non-human hominid – whether it be a pongine, hominine, or member of another hominid lineage – would be a huge deal. It would not just be one of the most newsworthy creatures to ever be discovered; it would also have enormous ramifications for our understanding of hominid evolution and potentially the human condition itself.

Are crypto-hominids a cultural phenomenon more than a zoological one? I’ve argued for both possibilities at different times. Whatever… for the purposes of the article you’re reading now, I hope we can agree that the discovery of such an animal would be high on any hypothetical ‘wants’ list. Image: Darren Naish.

Are crypto-hominids a cultural phenomenon more than a zoological one? I’ve argued for both possibilities at different times. Whatever… for the purposes of the article you’re reading now, I hope we can agree that the discovery of such an animal would be high on any hypothetical ‘wants’ list. Image: Darren Naish.

It would also – if relating to North America or northern Eurasia in particular – very likely have a significant impact on economy, land management and land use in those regions… or, you’d hope it would, anyway (who knows, given the current state of environmental protection in the USA). The hypothetical discovery of such an animal would also be regarded by many as one of the biggest ‘wins’ ever scored against ‘establishment science’, and thus could well be a bad thing (viz, “if scientists were wrong about this, what else could they be wrong about?”). And I’ll stop there before we dive into a rabbit-hole of conspiracy theories and coverups.

A big, flightless passerine. The majority of living bird species – over 60% of them – are passerines, or perching birds. This is the great group that includes crows, thrushes, warblers, finches, sparrows and so many others. For all their success, wide distribution and diversity, passerines are generally quite samey. There are no big, long-legged wading passerines, or heavy-bodied diving passerines or flightless running passerines, for example. Why this is so remains mysterious: passerines didn’t take to those niches because… well, they just didn’t. Does this mean that they couldn’t? As usual, we can come up with a few reasons as to why they were ‘constrained’ in evolutionary potential, but any one of those reasons could be overturned by some evolutionary deviant that refuses to pay attention to the rules.

Passerine birds are diverse, to a degree… here’s just a sample of their diversity. This is part of a giant montage that’s being built for   my in-prep textbook The Vertebrate Fossil Record  . Image: Darren Naish.

Passerine birds are diverse, to a degree… here’s just a sample of their diversity. This is part of a giant montage that’s being built for my in-prep textbook The Vertebrate Fossil Record. Image: Darren Naish.

And thus I submit that a particularly large, wholly flightless, cursorial passerine should make itself known to the world. It should be a record-holder as goes size, but not necessarily be that much bigger than the largest known passerines (like lyrebirds and ravens): I’m talking about a bird that weighs 3-5 kg and is thus similar in size to a large chicken. It should be a big, long-legged rail-babbler, quail-thrush or similar, and hence be a denizen of Wallacea or nearby.

Eupetes , the Malaysian rail-babbler. A hypothetical big, flightless passerine should be a close relative of this bird. Image: Francesco Verronesi, CC BY-SA 2.0 ( original here ).

Eupetes, the Malaysian rail-babbler. A hypothetical big, flightless passerine should be a close relative of this bird. Image: Francesco Verronesi, CC BY-SA 2.0 (original here).

A few recently extinct, island-dwelling passerines were flightless, so we do know that passerines have the evolutionary potential to follow this pathway. Such species (a bunting and a few New Zealand wrens… and possibly a few others) were all small (less than 40 g).

A western Asian giant salamander. Giant salamanders (cryptobranchids) are restricted today to eastern Asia (where Andrias occurs) and North America (where Cryptobranchus occurs). Hunting, human disturbance, habitat loss and deterioration, climate change and other issues are putting them into perilous decline, right at the same time as we’re discovering that some of them are species complexes. They were more widespread in the past than they are today, since fossils show that Andrias salamanders were widespread across Europe and Asia between about 28 and 2 million years ago.

An Asian giant salamander ( Andrias ) photographed in captivity. Record-holding specimens of  Andrias  can be 1.8 m long and exceed 60 kg, and some extinct species reached even larger sizes. Image: Markus Bühler.

An Asian giant salamander (Andrias) photographed in captivity. Record-holding specimens of Andrias can be 1.8 m long and exceed 60 kg, and some extinct species reached even larger sizes. Image: Markus Bühler.

While there are very good reasons for the decline and extinction of the animals in the areas concerned, some of the regions where they formerly occurred still have what look like suitable habitat today and are sparsely populated by people. Furthermore, extinct giant salamanders weren’t all denizens of fast-flowing, highly oxygenated streams like those inhabited by the modern populations. Some inhabited ponds and lakes. Ergo: I would really, really like there to be a west Asian cryptobranchid that comes from a habitat considered weird for the other living members of the group. And it doesn’t have to be a giant of 2 metres or more. A hellbender-sized species of 70 cm or so will do fine thank you very much.

Some extinct cryptobranchids - this is Zdeněk Burian’s reconstruction of  Andrias scheuchzeri  - inhabited European ponds and lakes. I’ve previously criticised this image for showing the animal as terrestrial. Since then, the proposal has been made that some extinct cryptobranchids (albeit not  A. scheuchzeri ) were significantly more terrestrial than living species. Image: (c) Zdeněk Burian.

Some extinct cryptobranchids - this is Zdeněk Burian’s reconstruction of Andrias scheuchzeri - inhabited European ponds and lakes. I’ve previously criticised this image for showing the animal as terrestrial. Since then, the proposal has been made that some extinct cryptobranchids (albeit not A. scheuchzeri) were significantly more terrestrial than living species. Image: (c) Zdeněk Burian.

Again, this is an area of special interest to cryptozoologists, since there have been occasional suggestions that stories, engravings and such from western Asia might reflect folk knowledge of unusually big salamanders in the region. In reality, the images and stories concerned are super-ambiguous and more likely refer to otters and god knows what else.

At left:  Andrias  skull. Image: Darren Naish. At right: Japanese giant salamander ( A. japonicus ) illustration by Y. de Hoev from 1887. Image: Y. de Hoev, public domain ( original here ).

At left: Andrias skull. Image: Darren Naish. At right: Japanese giant salamander (A. japonicus) illustration by Y. de Hoev from 1887. Image: Y. de Hoev, public domain (original here).

A living albanerpetontid. Everyone knows that there are three main groups of living amphibian: caecilians, salamanders and anurans (frogs and toads). But until (geologically) recently, there was a fourth group: the albanerpetontids, sometimes termed albies by those who work on them. Albanerpetontids were geographically widespread, their range including Eurasia, northern Africa and North America, and they were geologically long-lived too. The oldest are from the Middle Jurassic while the youngest are… well, we’ve known of Miocene fossil albanerpetontids for decades, have known of Pliocene specimens since 2005 (Venczel & Gardner 2005), and now know that at least one species persisted into the Pleistocene (Villa et al. 2018). The fact that their fossil record has been creeping towards the Recent means that the possibility of fossil and even extant Holocene specimens being discovered isn’t ridiculous, especially given the small size of these animals and hence tiny size of their bones.

New salamander species are occasionally discovered in Europe and Asia even now. It would be amazing if an animal suspected to be a ‘new salamander’ one day turned out to be a living albanerpetontid. These reconstructions were published by McGowan & Evans (1995). They might have erred in implying that the scales would be externally visible as shown here; more likely is that they were concealed by epidermis, as in other scaly fossil amphibians. Image: McGowan & Evans (1995).

New salamander species are occasionally discovered in Europe and Asia even now. It would be amazing if an animal suspected to be a ‘new salamander’ one day turned out to be a living albanerpetontid. These reconstructions were published by McGowan & Evans (1995). They might have erred in implying that the scales would be externally visible as shown here; more likely is that they were concealed by epidermis, as in other scaly fossil amphibians. Image: McGowan & Evans (1995).

To be frank, a live albanerpetontid wouldn’t be a particularly spectacular animal: it would be a tiny, slim, salamander-like amphibian less than 10 cm long, and it wouldn’t be much fun to watch since it would spend most of its time hiding and burrowing in leaf litter. But among herp-nerds it would be a huge deal. Live albanerpetontids were scaly-skinned (though the scales were not necessarily visible externally), with eyelids, and with adaptations in the snout, skull-roof, neck and body shape linked to head-first burrowing (McGowan & Evans 1995).

An artistic reconstruction of a live albanerpetontid…   produced for my in-prep The Vertebrate Fossil Record  . Image: Darren Naish.

An artistic reconstruction of a live albanerpetontid… produced for my in-prep The Vertebrate Fossil Record. Image: Darren Naish.

A Eurasian palaeognath. Palaeognaths are the big, flightless ratites (ostriches, emus and so on), the superficially gamebird-like, flight-capable tinamous, and their extinct relatives. A huge amount has been written about the evolutionary history and biogeography of these birds, since their distribution is curious and has resulted in all kinds of different models about how they might have spread around the world. I’ve written about this issue at length on previous occasion (the articles concerned being famous for generating the longest-ever comment threads in the history of TetZoo… though all of this is mostly wasted now, what with SciAm’s paywalling of the site, sigh). Living palaeognaths are absent from Eurasia, despite the former present in the region of ancient, flight-capable Paleogene taxa, extinct ostriches and others.

As this map shows, modern palaeognaths occurred everywhere until recently (except Antarctica) with the exception of northern North America and the cooler parts of Eurasia. Extinctions across Eurasia, Madagascar and New Zealand of course saw the disappearance of various members of the group. Image: Darren Naish.

As this map shows, modern palaeognaths occurred everywhere until recently (except Antarctica) with the exception of northern North America and the cooler parts of Eurasia. Extinctions across Eurasia, Madagascar and New Zealand of course saw the disappearance of various members of the group. Image: Darren Naish.

The fact that Paleogene Europe was home to many bird groups that no longer occur there but are now denizens of tropical regions elsewhere leads me to hope for a living palaeognath – a tinamou- or bustard-sized species – that descends directly from archaic Paleogene taxa and now lives in the Asian tropics. It should be a cryptic generalist with barred plumage and a mid-length bill and a reduced flight ability.

A gigantic, predatory, limbed amphisbaenian. Regular readers of TetZoo might know that I really like amphisbaenians: the mostly limbless, bullet-headed ‘worm lizards’ of the American tropics, Africa, and parts of southern Europe and western Asia. Amphisbaenian evolutionary history and biogeography has become increasingly complex in recent years as we’ve learnt a bunch of new stuff about their fossil history, genetics and anatomy. Among the weirdest of amphisbaenians are the ajolotes (or bipedids), the only extant group to possess limbs. These limbs are not small stumps or flaps (as they are in some other near-limbless, serpentine squamates) but well-developed, clawed forelimbs. According to some phylogenetic models, ajolotes are not the sister-group to limbless amphisbaenians but deeply nested within the limbless clade (Conrad 2008, Videl et al. 2008), in which case their limbedness – if you will – perhaps evolved from limbless ancestors. Add to this the fact that some amphisbaenians are robust-jawed, short-faced predators of vertebrates that ambush prey from beneath the surface and bite chunks from the bodies of surface-dwelling mammals and reptiles.

Bipes , an ajolote of Mexico (they might occur in parts of the USA as well). Three extant species are recognised. Image: Darren Naish.

Bipes, an ajolote of Mexico (they might occur in parts of the USA as well). Three extant species are recognised. Image: Darren Naish.

So then… where oh where are the giant, limbed, robust-skulled, vertebrate-eating amphisbaenians? By ‘giant’, I am not talking about a graboid-sized monster of several metres (though that would be nice), but a more reasonable animal of a mere 1.5 metres or so. Easily the stuff of nightmares. They could inhabit warm regions of any continent.

Carl Gans’s illustration of a burrowing ajolote, showing how the large, well-clawed forelimbs function in propulsion. This is clearly a Five-toed worm lizard  Bipes biporus ; the other extant species have four and three digits, respectively. Image:   Gans (1974)  .

Carl Gans’s illustration of a burrowing ajolote, showing how the large, well-clawed forelimbs function in propulsion. This is clearly a Five-toed worm lizard Bipes biporus; the other extant species have four and three digits, respectively. Image: Gans (1974).

Is there any reason to think that gigantic, predatory, limbed amphisbaenians might actually exist and await discovery? Nope. But I wish it were so. Regular readers might recognise that such creatures are denizens of the alternative-timeline Earth of the Squamozoic, but I’m sure that that’s coincidental.

What would a gigantic, predatory, limbed amphisbaenian look like? Like this, of course. Image: Darren Naish.

What would a gigantic, predatory, limbed amphisbaenian look like? Like this, of course. Image: Darren Naish.

An African or west Eurasian, long-beaked river dolphin. On several occasions within the history of odontocete cetaceans (‘toothed whales’), lineages have moved into brackish and estuarine environments, and eventually made the transition to committed freshwater life. There are the Asian Platanista species, the recently extinct Lipotes of China, and the tropical American Inia species. Once united within Platanistoidea and thought to be close kin, we know today that these animals represent at least three separate transitions to the freshwater environment (the term Platanistoidea is now restricted to the Platanista lineage alone). In addition, members of other groups – I’m thinking of the delphinid Orcaella – occur in rivers within parts of their range. There’s also a fossil beaked whale that might be indicative of freshwater specialisation in yet another odontocete group (Mead 1975).

River dolphins are pretty special looking. This is a Ganges river dolphin ( Platanista gangetica ). Image: Zahangir Alom / Marine Mammal Commission / National Oceanic and Atmospheric Administration, public domain ( original here ).

River dolphins are pretty special looking. This is a Ganges river dolphin (Platanista gangetica). Image: Zahangir Alom / Marine Mammal Commission / National Oceanic and Atmospheric Administration, public domain (original here).

In view of all this, why aren’t there river-dwelling dolphins in Africa, Europe or western Asia? Again, the answer seems to be… there just aren’t. A few fossil taxa suggest that such animals might have evolved if things had gone another way (there are fossil platanistoids from the Caucasus, for example). But I humbly submit that the great river systems of tropical Africa, the Tigris-Euphrates system of western Asia and the Danube, Po, Ebro, Dniester and others of southern Europe would be much improved if only we knew of their endemic riverine dolphins. I’m talking about a true riverine specialist, convergent with Inia and Platanista, with a long beak, spike-like teeth, reduced eyesight, the works. And if you want to play fast and loose with antiquarian literature and anecdote, there are references in the literature to ‘river dolphins’ in the Nile and there are even one or two eyewitness accounts from central Europe that describe long-beaked ‘dolphins’ seen in rivers and lakes.

If there are extant west Eurasian or African river dolphins, they should look like this. This is a hypothetical species, modelled on the American  Inia  and Asian  Platanista . Image: Darren Naish.

If there are extant west Eurasian or African river dolphins, they should look like this. This is a hypothetical species, modelled on the American Inia and Asian Platanista. Image: Darren Naish.

An endoparasitic tetrapod. Tetrapods have become parasites on several occasions. Vampire bats are parasites of birds and mammals, and it’s even been argued that some blood- and milk-eating human populations can be considered parasites of the mammals they rely on (though the mammals concerned are domesticated, so it’s complicated). Elsewhere among vertebrates, everyone knows about the parasitic catfishes that invade the gills of other actinopterygian fishes and even the urethras of mammals; less familiar is the fact that other actinopterygians can, on rare occasion, become trapped inside the bodies of other vertebrates and then make a successful living. Yes, you read that right. I have in mind the case where two Snubnosed or Pugnose eels Simenchelys parasitica were discovered living inside the heart of a mako shark (Caira et al. 1997; see also Eagderi et al. 2016). This eel is not – despite its name* – ordinarily an internal parasite: this was a case of facultative endoparasitism!

At left: a snubnosed eel found living inside the heart of a shark. Eels are not tetrapods, it’s true. But here’s evidence that aquatic vertebrates can become endoparasites. Image: Caira  et al . (1997). At right: an aquatic typhlonectid caecilian. Surely it’s only a matter of time before we discover an endoparasitic one of those as well. Image: Neil Phillips.

At left: a snubnosed eel found living inside the heart of a shark. Eels are not tetrapods, it’s true. But here’s evidence that aquatic vertebrates can become endoparasites. Image: Caira et al. (1997). At right: an aquatic typhlonectid caecilian. Surely it’s only a matter of time before we discover an endoparasitic one of those as well. Image: Neil Phillips.

There are all kinds of reasons why a tetrapod couldn’t become an endoparasite, respiration being high on the list. A hypothetical endoparasitic tetrapod would have to be small, with remarkable tolerance of unusual chemical and thermal conditions, with low oxygen requirements, and most likely with the ability to respire cutaneously or via gills. In other words, it should be the world’s weirdest caecilian. As if caecilians aren’t weird enough, I’d love there to be small, endoparasitic caecilians. Given that some caecilians are already aquatic gill-breathers that will consume the tissues of fish (exhibit A: the sequence from River Monsters where Jeremy Wade discovers swarming typhlonectid caecilians in the carcass of a large fish), I predict these animals to be aquatic, South American species that parasitise actinopterygians and aquatic mammals, like Inia the river dolphin.

* Snubnosed eels were given the name ‘parasitica’ because they opportunistically latch on to the bodies of larger fish and eat away at the flesh. They were not thought to ever be proper internal parasites prior to 1992.

And that’s where I’ll stop for now. I actually came up with a list containing numerous additional ‘wish list’ animals but time is against me. Maybe I’ll cover them in another article. Whatever, this was all a bit of fun and I hope you enjoyed it.

For TetZoo articles relevant to the issues covered here, see…

PS I’m going to stop linking to the SciAm run of TetZoo articles soon, because I cannot access them at all and they’re now all but useless. They all need to be relocated to an open-access site.

Thanks to those supporting this work – and the very blog itself – via pledges at patreon. You can support what I do and see works-in-prep behind the scenes, via pledges as small as $1 per month.

Refs - -

Caira, J. N., Benz, G. W., Borucinska, J. & Kohler, N. E. 1997. Pugnose eels, Simenchelys parasiticus (Synaphobranchidae) from the heart of a shortfin mako, Isurus oxyrinchus (Lamnidae). Environmental Biology of Fishes 49, 139-144.

Conrad, J. 2008. Phylogeny and systematics of Squamata (Reptilia) based on morphology. Bulletin of the American Museum of Natural History 310, 1-182.

Eagderi, S., Christiaens, J., Boone, M., Jacobs, P. & Adriaens, D. 2016 Functional morphology of the feeding apparatus in Simenchelys parasitica (Simenchelyinae: Synaphobranchidae), an alleged parasitic eel. Copeia 104, 421-439.

Gans, C. 1974. Biomechanics: An Approach to Vertebrate Biology. J. B. Lippincott Company, Philadelphia, Toronto.

Graham, G. L. 2002. Bats of the World. St. Martin’s Press, New York.

Mackal, R. P. 1987. A Living Dinosaur? In Search of Mokele-Mbembe. E. J. Brill, Leiden.

McGowan, G. J. & Evans, S. E. 1995. Albanerpetontid amphibians from the Cretaceous of Spain. Nature 373, 143-145.

Mead, J. G. 1975. A fossil beaked whale (Cetacea: Ziphiidae) from the Miocene of Kenya. Journal of Paleontology 49, 745-751.

Naish, D. 2017. Hunting Monsters: Cryptozoology and the Reality Behind the Myths. Arcturus, London.

Simons, E. L. & Ettel, P. C. 1970. GigantopithecusScientific American 222 (1), 77-84.

Venczel, M. & Gardner, J. D. 2005. The geologically youngest albanerpetontid amphibian, from the Lower Pliocene of Hungary. Palaeontology 48, 1273-1300.

Vidal, N., Azvolinsky, A., Cruaud, C. & Hedges, S. B. 2008. Origin of tropical American burrowing reptiles by transatlantic rafting. Biology Letters 4, 115-118.

Villa, A., Blain, H.-A. & Delfino, M. 2018. The Early Pleistocene herpetofauna of Rivoli Veronese (Northern Italy) as evidence for humid and forested glacial phases in the Gelasian of Southern Alps. Palaeogeography, Palaeoclimatology, Palaeoecology 490, 393-403.

Whatever Happened to the Kabomani Tapir?

As a regular TetZoo reader, you’ll no doubt be aware of Tapirus kabomani, the (alleged) new South American tapir species named by Mario Cozzuol and colleagues in 2013 (Cozzuol et al. 2013).

Tapirus : poster-child for TetZoo Park. Image: Patrick Murphy.

Tapirus: poster-child for TetZoo Park. Image: Patrick Murphy.

T. kobamani – popularly termed simply the Kabomani tapir (the names Little black tapir or Black dwarf tapir are also available; read on) – was described as smaller and darker than other South American tapirs, and as possessing a few distinctive osteological features, like a broad forehead and frontal bones that are more inflated than those of other tapirs. Its validity as a distinct species is, however, controversial, as we’ll see.

There’s TetZoo HAVE YOU HEARD ABOUT THE NEW TAPIR merchandise.   Go here.

There’s TetZoo HAVE YOU HEARD ABOUT THE NEW TAPIR merchandise. Go here.

I wrote about the initial naming and description of T. kabomani back here at TetZoo ver 3 (warning: now paywalled). Immediately there was a reasonable amount of scepticism from other zoologists familiar with tapirs and their biology, distribution and systematics – many of whom argued that T. kabomani was similar enough to the Brazilian or Lowland tapir T. terrestris to be considered conspecific with it – and also a claim that exactly the same sort of tapir had already been described by another zoologist (namely, Marc van Roosmalen).

One of several  T. kabomani  images captured by remote cameras: from  Cozzuol  et al . (2013) . Image:  Cozzuol  et al . (2013) .

One of several T. kabomani images captured by remote cameras: from Cozzuol et al. (2013). Image: Cozzuol et al. (2013).

But what has happened since 2013? Well, quite a bit: several studies evaluating the status of T. kabomani have been published since Cozzuol et al.’s initial paper of 2013. What do these various studies state, and what do they conclude? Let’s look at each of the studies in turn. I’ve done my best to summarise the relevant papers, and to keep my summaries brief.

  • As noted above, Marc van Roosmalen has been stating right from the time that kabomani was first described that it is identical with another alleged small tapir – T. pygmaeus, termed the Black dwarf tapir by van Roosmalen – that he named (online) in 2002, briefly diagnosed and described in popular books of 2008 and 2013, and formally published within a section of another book of 2013 (Van Roosmalen & Van Hooft 2013). Van Roosmalen (2014) petitioned the ICZN (case 3650) to have the 2013 book in question – Barefoot Through the Amazon – On the Path of Evolution – registered as part of the ‘Official List of Works Approved as Available for Zoological Nomenclature’, and thus to have T. pygmaeus endorsed as a valid, official name with priority over T. kabomani. A ruling on this proposal has not been made, to my knowledge. Van Roosmalen again stated his view that these two forms are synonymous in a 2015 publication (Van Roosmalen 2015).

The Black dwarf tapir, as illustrated in Marc van Roosmalen’s 2013 book. Image: van Roosmalen (2013).

The Black dwarf tapir, as illustrated in Marc van Roosmalen’s 2013 book. Image: van Roosmalen (2013).

  • Robert Voss et al. (2014) were highly critical of Cozzuol et al.’s (2013) case for the validity of T. kabomani, literally starting their paper with reference to Carl Sagan’s aphorism that “extraordinary claims require extraordinary evidence” (p. 893). To be honest, I’m not sure that the reporting of a new species of tapir is as extraordinary as they think it is but… whatever, they argued that none of the molecular, morphological or ethnological evidence compiled by Cozzuol et al. (2013) withstood scrutiny. Their most interesting contention was that kabomani is not ‘distinct enough’ from T. terrestris to warrant species-level separation (the sequence divergence in Cytb amounting to 1.3%), and that both T. kabomani and the Mountain or Woolly tapir T. pinchaque are not phylogenetically separate from T. terrestris, both failing to be recovered as reciprocally monophyletic (Voss et al. 2014). Remember that this affects T. pinchaque as well as T. kabomani: we’ll be coming back to that point.

This section of Voss  et al .’s (2014) molecular phylogeny shows  T. pinchaque  and  T. kabomani  as poorly differentiated from  T. terrestris . Image: Voss  et al . (2014).

This section of Voss et al.’s (2014) molecular phylogeny shows T. pinchaque and T. kabomani as poorly differentiated from T. terrestris. Image: Voss et al. (2014).

  • Mario Cozzuol et al. (2014) published a response to Voss et al. (2014). With regard to Voss et al.’s (2014) contention (“Have several generations of Neotropical mammalogists really failed to recognise a species of Recent megafauna that is said to be widely distributed in Amazonia?”), their specific response was: “The answer is, simply, yes. Specifically, they failed, as many others have done for many years, to listen to the local people more carefully; those people have been aware of the existence of this species for a long time” (p. 899). Cozzuol et al. (2014) re-iterated their view that kabomani is morphologically distinct (they noted in particular its sagittal crest), and that it is recognised as distinct by various Amazonian peoples. Regarding Voss et al.’s (2014) finding that kabomani is nested within T. terrestris, Cozzuol et al. (2014) reported that different molecular trees were recovered depending on which tapir taxon was used as the outgroup, and that the nesting of kabomani within T. terrestris did not disprove its status as a distinct species given that T. pinchaque (the Mountain tapir, universally regarded as a distinct species) was found to be intractable from the terrestris-kabomani clade based on genetic data (Cozzuol et al. 2014).

Portrait of  T. kabomani , produced by G. Braga to accompany  Cozzuol  et al .’s (2013)  original paper. Image:  Cozzuol  et al . (2013) .

Portrait of T. kabomani, produced by G. Braga to accompany Cozzuol et al.’s (2013) original paper. Image: Cozzuol et al. (2013).

  • Manuel Ruiz-García et al. (2015) examined mitochondrial gene diversity across all South American tapirs, their aim being to better understand the genetic history of the group and thus its evolution, systematics and conservation biology. They included data from five kabomani specimens: two were the Brazilian specimens analysed by Cozzuol et al. (2013), and the others were individuals from Colombia, Peru and Ecuador (Ruiz-García et al. 2015). They found kabomani tapirs to be “more closely related to T. terrestris than to the other tapir species”, reported “significant differences with [DN – I think they meant ‘from’] T. terrestris as well as with [DN – surely ‘from’] T. pinchaque” (p. 11), but overall found kabomani tapirs to “yield lower genetic distances with regard to T. terrestris than did T. pinchaque” (p. 14). In other words, kabomani tapirs were not – in their view – genetically ‘distinct enough’ to warrant species status and should more reasonably be considered a distinct population of T. terrestris. This view was modified later in the text where they specifically stated (and depicted) kabomani tapirs as a clade within T. terrestris, the divergence of the kabomani lineage being suggested to have occurred between 1.3 million and 360,000 years ago (p. 18). Such a divergence date is young relative to other divergences between extant tapir species (some of you might recall date of divergence being deemed relevant in the debate surrounding white rhino phylogeny and taxonomy). These authors also provided a lengthy critique of anatomical criteria used by Cozzuol et al. (2013) to differentiate T. kabomani, arguing that some ‘kabomani-type’ tapirs did not have the morphological features supposedly diagnostic for this taxon, and furthermore than some small, ‘kabomani-type’ animals are not of the genetic kabomani group. Bottomline: kabomani “is a particular lineage within T. terrestris” (p. 34), and it is not morphologically well differentiated from the rest of T. terrestris, some other populations of which look kabomani-like.

Ruiz-García  et al .’s (2015) maximum likelihood tree, incoporated mitochondrial gene data for 93 tapir specimens.  T. pinchaque  is blue,  T. terrestris  is red,  T. kabomani  is green, and  T. bairdii  is purple. Note that  kabomani  is nested within  T. terrestris . Image: Ruiz-García  et al .’s (2015).

Ruiz-García et al.’s (2015) maximum likelihood tree, incoporated mitochondrial gene data for 93 tapir specimens. T. pinchaque is blue, T. terrestris is red, T. kabomani is green, and T. bairdii is purple. Note that kabomani is nested within T. terrestris. Image: Ruiz-García et al.’s (2015).

  • Dumbá et al. (2018) analysed skull shape variation in living tapir species (though they also included a few fossil ones too), and specifically analysed kabomani. They found kabomani skulls to have some overlap in morphospace with T. terrestris though noted that both could still be distinguished, in part because of kabomani’s broad forehead. In some landmark-based analyses, the kabomani sample overlapped almost entirely with the region of morphospace occupied by T. terrestris. The assumption of this study appears to be that kabomani is distinct and only similar to T. terrestris when certain sets of cranial landmarks are used (note that Mario Cozzual is the study’s last author). Another interpretation could be that kabomani overlaps so extensively with T. terrestris that it should be regarded as a poorly differentiated ‘extension’ of the morphospace occupied by T. terrestris.

The landmark-based morphometric work published recently by Dumbá  et al . (2018) shows  T. kabomani  to overlap quite extensively with the morphospace occupied by  T. terrestris . Image: Dumbá  et al . (2018).

The landmark-based morphometric work published recently by Dumbá et al. (2018) shows T. kabomani to overlap quite extensively with the morphospace occupied by T. terrestris. Image: Dumbá et al. (2018).

What, then, to conclude? By now you’ve surely heard, on a great many occasions, the contention that the entities we call ‘species’ do not have a consistent, well defined definition across all tetrapods, let alone across all animals or all organisms. Whether a given population warrants recognition as a ‘species’ is still, to some considerable degree, a subjective issue. Having gotten that caveat out of the way, most (note: most) mammalogists would agree that the minor molecular and morphological differences separating the Kabomani tapir from T. terrestris are not compelling, and it does appear most likely that it is a variant, morph or lineage of T. terrestris. However…

The Mountain or Woolly tapir was posited by  Cozzuol  et al . (2013)  as closer to  T. terrestris  than is  T. kabomani , but the inverse was recovered by Ruiz-García  et al . (2015). Image: Just Chaos, CC BY-SA 2.0 (original  here ).

The Mountain or Woolly tapir was posited by Cozzuol et al. (2013) as closer to T. terrestris than is T. kabomani, but the inverse was recovered by Ruiz-García et al. (2015). Image: Just Chaos, CC BY-SA 2.0 (original here).

Problem 1: Voss et al.’s (2014) initial claim that the Mountain tapir is as much as part of T. terrestris as is kabomani was always problematic. After all, everyone agrees that the Mountain tapir should be retained as a valid species; if the Mountain tapir were to be regarded as part of T. terrestris, people would likely use special pleading to keep it distinct… which would, in turn, then negate the claim that kabomani was not worthy of species status. However, the more comprehensive analysis compiled by Ruiz-García et al. (2015) seems to have resolved this issue. Problem 2: the implication that the recovery of kabomani as a lineage within T. terrestris automatically negates its status as a species is not entirely fair or technically correct, since there are a great many animal populations we term ‘species’ that are not monophyletic and/or not outside other populations also termed ‘species’. A classic example is the Polar bear Ursus maritimus (generally found in studies to be nested within the Brown bear U. arctos.) but there are many, many others. In other words, finding kabomani to be a lineage within T. terrestris does not automatically negate a species-level status. But is it ‘distinct enough’ to be regarded as a ‘species’ all its own? My conclusion from all the work discussed above: no, no it is not, alas.

Tapirus terrestris  is a pretty variable animal, seemingly with a complex evolutionary history and a degree of morphological variation that’s only now beginning to come to light. This captive individual is from Chester Zoo, UK. Image: Darren Naish.

Tapirus terrestris is a pretty variable animal, seemingly with a complex evolutionary history and a degree of morphological variation that’s only now beginning to come to light. This captive individual is from Chester Zoo, UK. Image: Darren Naish.

And that is where we end for now. Tapirs have been covered quite a few times on TetZoo now, though once again I will note that many of the articles concerned are now paywalled due to a recent decision made at Scientific American blogs. If you can access them, the articles are here…

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Refs - -

Cozzuol , M. A., Clozato, C. L. , Holanda, E. C., Rodrigues, F. H. G., Nienow, S., de Thoisy, B., Redondo, R. A. F. & Santos, F. R. 2013. A new species of tapir from the Amazon. Journal of Mammalogy 94, 1331-1345.

Cozzuol, M. A., de Thoisy, B., Fernandes-Ferreira, H., Rodrigues, F. H. G. & Santos, F. R. 2014. How much evidence is enough evidence for a new species? Journal of Mammalogy 95, 899-905.

Dumbá, L. C. C. S., Parisi Dutra, R. & Cozzuol, M. A. 2018. Cranial geometric morphometric analysis of the genus Tapirus (Mammalia, Perissodactyla). Journal of Mammalian Evolution https://doi.org/10.1007/s10914-018-9432-2

Ruiz-García, M., Castellanos, A., Agueda Bernal, L., Navas, D., Pinedo-Castro, M. & Mark Shostell, J. 2015. Mitochondrial gene diversity of the mega-herbivorous species of the genus Tapirus (Tapiridae, Perissodactyla) in South America and some insights on their genetic conservation, systematics and the Pleistocene influence on their genetic characteristics. Advances in Genetic Research 14, 1-51.

Van Roosmalen, M. G. M. 2014. Case 3650: Tapirus pygmaeus Van Roosmalen & Van Hooft in Van Roosmalen, 2013 (Mammalia, Perissodactyla, TAPIRIDAE): proposed confirmation of availability of the specific name and of the book in which this nominal species was proposed. Bulletin of Zoological Nomenclature 71, 84-87.

Van Roosmalen, M. G. M. 2015. Hotspot of new megafauna found in the Central Amazon (Brazil): the lower Rio Aripuanã Basin. Biodiversity Journal 6, 219-244.

Van Roosmalen, M. G. M. & Van Hooft, P. 2013. New species of living tapir, the dwarf tapir (Mammalia: Tapiridae) from the Brazilian Amazon, in Van Roosmalen, M. G. M. (ed), Barefoot Through the Amazon – On the Path of Evolution. CreateSpace, North Charleston SC, pp. 400-404.

Voss, R. S., Helgen, K. M. & Jansa, S. A. 2014. Extraordinary claims require extraordinary evidence: a comment on Cozzuol et al. (2013). Journal of Mammalogy 95, 893-898.