Multiple new species of large, living mammal (part I)

Arguably the most exciting concept in the entire field of zoology is the thought that new large terrestrial tetrapod species await discovery. And despite statements from journalists and scientists, history demonstrates that the continued discovery of such animals is not an extraordinary or unexpected event. You will know this if you are familiar with such animals as the Saola Pseudoryx nghetinhensis (named in 1993), Giant muntjac Megamuntiacus vuquangensis (named in 1994), Truong Son muntjac Muntiacus truongsonensis (named in 1998), Leaf deer M. putaoensis (named in 1999), Dingiso Dendrolagus mbaiso (named in 1995: shown in adjacent image), Small red brocket Mazama bororo (named in 1996), Arunachal macaque Macaca munzala (named in 2004) and Kipunji Rungwecebus kipunji (named in 2005).

Several studies have emphasized the fact that new terrestrial mammal species are not uncommon (Heuvelmans 1983, Pine 1994, Patterson 2000, 2001, 2002, Collen & Gittleman 2004), and it is not true that all such taxa are small-bodied, nor are they all rodents and bats, nor are they all discovered in molecular laboratories or museum collections (for the record, in the discussion here I am only referring to new species discovered in the field, and not those that are discovered in museum drawers, or result from taxonomic revisions [such as Aggarwal et al.'s (2007) naming of the two new Indian wolf species, Canis himalayensis and C. indica. That's right, two new extant canid species named this year]).

New terrestrial mammals, such as those listed above, have come from SE Asia, tropical Africa and New Guinea, but one of the most notable hotspots has been Amazonia. Research here had led to the description of multiple new opossums, shrews, bats, rodents and primates, with the recognition of multiple new species of the latter group perhaps receiving most attention. On this issue, few living people have contributed so much to the discovery and documentation of new terrestrial mammal species as Dutch primatologist Dr Marc van Roosmalen [shown at left: but not the little furry chap, that's a woolly monkey]. If you know anything about the new mammal species that have been named within the last 20 years, or about the primates of Amazonia, you will already have read an awful lot about him. Articles and items about van Roosmalen and his research have appeared in Time Magazine, National Geographic, on CNN and BBC news. He has been the recipient of many grants, and is well decorated with impressive awards and titles. His contributions have been honoured by other mammalogists: Voss & da Silva (2001), for example, named the tree porcupine Coendou roosmalenorum after van Roosmalen and his son Tomas (free pdf here).

The discoveries that have kept van Roosmalen in the international science news have predominantly been of monkeys: he has described and named some of these new species himself, while in other cases they have been described and named by others. The first of his discoveries, the Black-crowned dwarf marmoset Callithrix humilis, was named in 1998 and has since been argued to represent a new genus, Callibella (free pdf here). The Satarè marmoset Mico (Callithrix) saterei, was discovered by van Roosmalen and named by José de Sousa e Silva Júnior and Maurício de Almeida Noronha in 1998 (free pdf here). Two new species of Callithrix, the Manticore marmoset C. manicorensis and Rio Manicoré marmoset C. acariensis were named in 2000 by van Roosmalen and colleagues (free pdf here), and two new titi monkeys, Prince Bernhard's titi monkey Callicebus bernhardi and Stephen Nash's titi monkey C. stephennashi [shown in adjacent image], were named by van Roosmalen and colleagues in 2002 (free pdf here).

Marmosets and titi monkeys are one thing. But what if the same worker had also discovered multiple new species of large mammal*? Long-time readers of Tet Zoo will recall my ver 1 post Meet peccary # 4. The 1975 announcement of the discovery of a new living peccary species - the Chacoan peccary Catagonus wagneri - has been hailed as one of the most significant mammalogical discoveries of the 20th century. So the 2004 news that what appears to be another large extant peccary species was really really interesting, to say the least. Van Roosmalen learnt of the new peccary by listening to the local Caboclos people, and was eventually able to observe and photograph the animal in the wild, and later still able to procure material of the species for genetic analysis. The latest news on this species - it is to be formally named the Giant peccary Pecari maximus [it's pictured at left] - is that a full technical paper is in press for Bonner Zoologischen Beiträge (a pdf of the preprint version is available, free, here). Genetic work indicates that this species diverged from its closest living relative, the Collared peccary P. tajacu, about 1.5 million years ago: easily enough time for it to be considered a separate species if, that is, we relied only on some sort of subjective phylogenetic distance measurement as a means of determining status.. which we don't.

* Given that most mammals weigh less than 1 kg, a 'large mammal' could perhaps be regarded as anything bigger than this. The animals I have in mind in this discussion range from a few kg to several 10s of kg.

But now we come to the big news. While the discovery of a new living peccary species is big, this is just the tip of the iceberg. In fact, van Roosmalen has now gathered evidence indicating the presence of a great many new large Amazonian mammals. We are talking several new monkeys, additional new peccaries, new deer, a new tapir, a new dolphin, a new giant anteater, a new big cat... in an effort to bring this new research to wider attention, I'm going to review many of these new species here on the blog, almost the first place they've been brought to attention. 'Almost'? Marc van Roosmalen and I have been corresponding for a while now, and the main reasons for writing this blog post (and the subsequent two or three or four) is to bring Marc's new website to wider attention. It provides fuller detail on all of the new animals, discusses the other species he has discovered, and also includes links to free pdfs and news articles. Most of this information is entirely new, though summaries and snippets have appeared before. Some of the new animals, though not all of them, were discussed in Karl Shuker's The New Zoo.

The anta-pretinho

We've already seen the Giant peccary. But that's not all among the ungulates. Scattered here and there in the literature on Marc's discoveries are references to a new tapir, but because nothing has been forthcoming it's even been suggested that these mentions might have been confused references to one of the new peccaries. They're not. Marc really does seem to have a new species of tapir, and has procured a skull that will form the basis of a holotype. Dubbed the anta-pretinho by local people, it is a dwarf tapir endemic to the Rio Aripuanã basin, and is both smaller and far darker in colour than the two recognised Amazonian Tapirus species (Brazilian tapir T. terrestris and Baird's tapir T. bairdii) [adjacent image shows reconstruction of anta-pretinho].

The new dwarf form also differs from T. terrestris in lacking white tips to its ears (Padilla & Dowler 1994, Emmons 1999); in having proportionally shorter jaws and nasal bones, and in its unique tooth count (it lacks some of the upper premolars and molars, and lower molars, present in all other tapirs). T. terrestris possesses a unique form of sagittal crest (unique both among tapirs, and among mammals in general) where the embryonic crest forms along the dorsal skull roof midline, rather than from two temporal ridges that migrate medially and then coalesce (Holbrook 2002), and it would prove interesting to see whether the dwarf tapir shares this derived pattern of development. In the Rio Aripuanã basin, the new dwarf form is sympatric with T. terrestris: Marc suggests that the latter species has only invaded the basin relatively recently, and that the dwarf taxa is an older endemic.

Of the four named extant tapir species, the Malayan tapir T. indicus wasn't named until 1819, the Mountain tapir T. pinchaque not until 1829, and Baird's tapir T. bairdii not until 1865 (it was originally Elasmognathus bairdii Gill, 1865) [adjacent image shows Baird's tapir]. As you'll know if you're familiar with Heuvelmans' On the Track of Unknown Animals, these namings all post-date 'Cuvier's rash dictum': Baron George Cuvier's 1812 proclamation that no new large land animals remained to be discovered. Actually, loads more extant tapir species have been named more recently than that (including Elasmognathus dowii Gill, 1870, T. spegazzinii Ameghino, 1909 and T. anulipes Hermann, 1924), but all have either been relegated to the status of subspecies, or have been sunk into synonymy. One valid subspecies of T. terrestris, T. t. columbianus, was first named by Hershkovitz (1954). The anta-pretinho, though yet to be formally named and described, will be the first new extant, valid tapir species named since 1865.

More in part II: more peccaries, new brockets, dwarf manatee, dwarf boto, black giant otter and others. Part III will cover lots of new monkeys, and part IV the new giant anteater and the onça-canguçú, a new big cat. Oh yes.

Refs - -

Aggarwal, R. K., Kivisild, T., Ramadevi, J. & Singh, L. 2007. Mitochondrial DNA coding region sequences support the phylogenetic distinction of two Indian wolf species. Journal of Zoological Systematics and Evolutionary Research 45, 163-172.

Collen, B., Purvis, A. & Gittleman, J. L. 2004. Biological correlates of description dates in carnivores and primates. Global Ecology and Biogeography 13, 459-467.

Emmons, L. H. 1999. Neotropical Rainforest Mammals: A Field Guide (Second Edition). University of Chicago Press, Chicago & London.

Hershkovitz, P. 1954. Mammals of northern Colombia. Preliminary report no. 7 tapirs (genus Tapirus), with a systematic review of American species. Proceedings of the United States National Museum 103, 465-496.

Heuvelmans, B. 1983. How many animal species remain to be discovered? Cryptozoology 2, 1-24.

Holbrook, L. T. 2002. The unusual development of the sagittal crest in the Brazilian tapir (Tapirus terrestris). Journal of Zoology 256, 215-219.

Padilla, M. & Dowler, R. C. 1994. Tapirus terrestris. Mammalian Species 481, 1-8.

Patterson, B. D. 2000. Patterns and trends in the discovery of new Neotropical mammals. Diversity and Distributions 6, 145-151.

- . 2001. Fathoming tropical biodiversity: the continuing discovery of Neotropical mammals. Diversity and Distributions 7, 191-196.

- . 2002. On the continuing need for scientific collecting of mammals. Journal of Neotropical Mammalogy 9, 253-262.

Pine, R. H. 1994. New mammals not so seldom. Nature 368, 593.

Voss, R. S. & Da Silva, M. N. F. 2001. Revisionary notes on Neotropical porcupines (Rodentia: Erethizontidae). 2. A review of the Coendou vestitus group with descriptions of two new species from Amazonia. American Museum Novitates 3351, 1-36.