The 9,999th Reptile

Click here to view this post in Spanish
Haga clic aquí para ver este mensaje en Español

Number of new snake species by decade, with highlights
Data from The Reptile Database

Linnaeus's 1758 Systema Naturae, the starting point of zoological nomenclature, described 118 species of reptiles, including 74 snakes (not counting the limbless lizards and amphibians he included in the same group). It took over 100 years for the number of described species of snakes to reach 1000, an event that probably passed without much notice amid the American Civil War. Since that time, new snake species descriptions have been added at the rate of about 15 a year, although molecular taxonomy has increased this pace over the last few decades. The trends for snakes and for reptiles as a whole have been similar, and on July 9th, 2014, a team of American, German, Lao, and Vietnamese scientists described a new species of gecko from Laos, which the journal Herpetological Review reported as the 10,000th reptile species. Needless to say, I was excited, but I was also extremely disappointed because I had been so hoping that it would be a snake! Rather than admit defeat and scrap this planned post, I emailed Peter Uetz at The Reptile Database, an incredible resource that I've praised before, to confirm that this gecko was indeed #10,000. As usual for taxonomy and as I should have suspected, the reality was a bit more complicated.

Although Cyrtodactylus vilaphongi was the 10,000th reptile species for a while, the order and position of entries in The Reptile Database is constantly changing. Although new species get added to the end of the list, it's common for two or more existing species to get synonymized or merged, which moves the position of all subsequent species up. Furthermore, sometimes species that were described long ago and subsequently synonymized are revalidated, leading to 'new' species that aren't really new in the sense that they have existed before. Finally, often existing species get split up, leading to additions that aren't as dramatic as legitimate new discoveries. This last complication is on the rise now that molecular systematics has enabled us to describe the cryptic diversity of some lineages, which are not all that morphologically distinct but may contain considerable genetic diversity.

At the time of my email to Peter last month, C. vilaphongi was the 9988th species, and (happily), a new snake, Siphlophis ayauma, was #10,000. Although this has probably changed again by now, I'm going to operate under the assumption that, since we can't really say with certainty that any particular species was #10,000, if it was a snake, it was probably one of the 11 brand new snake species that have been described so far this year. You can read about many of these on the blog 'Species New to Science', but I'm going to highlight them in a little more detail here.

Rhabdophis guangdongensis
From Zhu et al. 2014

The first new snake described this year, Rhabdophis guangdongensis, was collected by a team of Chinese herpetologists in Guangdong Province in 2008. The reason it wasn't described until the February 20th issue of the journal Zootaxa is because, as is often the case, it takes a couple of years to compare both the anatomy and the DNA of a suspected new species to reference specimens of known similar species and establish that the species really is new. In the past, particularly prior to the internet, the difficulty of doing this was a huge problem, resulting in close to half of all 'new' species later being invalidated as duplicates. The genus Rhabdophis  is distributed in southern and eastern Asia, and this is the 21st species. It's an extremely interesting genus from a chemical ecology perspective, because at least one species sequesters defensive chemicals from its prey and provisions them to its young (which I wrote about for Scientific American shortly after I started this blog). A recent paper by Yosuke Kojima and Akira Mori on the Japanese species R. tigrinus showed that females periodically leave wetlands for forest streams where they forage on toads, likely to obtain the necessary toxins for provisioning their offspring. The new species also has specialized structures, known as nuchal glands, on the back of its neck, so presumably it stores bufotoxins there as well, although this has yet to be verified.

Opisthotropis durandi
From Teynié et al. 2014

On March 3rd, a team of French, German, and Vietnamese scientists published a description of Opisthotropis durandi, a highly aquatic snake collected from the base of a waterfall in northern Laos. This is the seventh species of Opisthotropis described in the past 20 years, and the first from Laos (although other species are likely to occur there based on their occurrence in surrounding countries). Like the new Rhabdophis, it is also the 21st species in its genus. It is important to realize that, like most species new to science, this snake was already known by local people. It is called Ngou Koung or Ngou Kung, meaning “shrimp snake”, suggesting that it may eat shrimp. The pools at the base of the waterfall where the first specimen was found contained many small shrimp.

Eutrachelophis bassleri and its weird penis
From Myers & McDowell 2014
A color photo of E. bassleri was published in Echevarría & Venegas 2015

Harvey Bassler, a petroleum geologist, explored many of the Amazon's upper tributaries for his work during the 1920s and 30s, during which time he collected over 4,200 snakes on the side. Bassler deposited his magnificent collection in the American Museum of Natural History in 1934, and on March 6th this year Charles Myers and Samuel McDowell published a monograph in the Bulletin of the American Museum of Natural History describing a species of snake collected by Bassler in 1927, for which they erected a new genus, Eutrachelophis (‘beautiful-necked snakes’’). They also placed in this genus a species originally described by Boulenger in 1905, Rhadinaea steinbachi, which they renamed Eutrachelophis steinbachi. Although the two species (and a third, yet undescribed) have very similar skeletons, muscles, glands, viscera, and markings, they probably would have been placed in separate genera had they been described in the 19th or early 20th century because their hemipenes are so different. E. steinbachi has long but relatively normal-looking hemipenes, whereas E. bassleri  has extremely unusual heimpenes tipped with a dome-like structure so strange (at least within the world of snake hemipenes) that the authors wrote "we have seen nothing quite like [it]." Hemipenes were traditionally considered one of the most taxonomically-important structures in snakes¹ because they were considered to be evolutionarily neutral (that is, unlikely to change in response to selection), but a growing awareness that evolution by both natural and especially sexual selection can influence the morphology of male genitalia led these authors to recognize that these two snakes were in fact close relatives. Although we await molecular confirmation, the authors propose a mechanism by which differential expression of Hox genes² could cause such a rapid divergence in hemipenal morphology between two sister species.

Siphlophis ayauma
From Sheehy et al. 2014

On January 12th, 2008, a group of American and Ecuadorian herpetologists stopped for lunch at a grilled-chicken restaurant in Paute, Azuay province, Ecuador. They noticed a peculiar sun-faded snake on display in a jar of alcohol that they couldn't quite put a name to. Following negotiation with the restaurant owner, the specimen was acquired and determined to belong to the genus Siphlophis, but could not be identified to any known species. A few months later, another specimen was found alive about 100 miles to the north, and two more were discovered in 2011 about the same distance to the south. A fifth individual is now recognized to have been hiding out unnoticed in the collection of the Museo de Zoología, Pontificia Universidad Católica del Ecuador. Because of its red-banded head and its occurrence in the mountains near cold (achachay) streams, the new species was named Siphlophis ayauma after the Kichwa spirit Aya Uma, a good spirit devil who derives strength from nature, particularly from cold mountain pacchas (cascades) and is represented in Kichwa folklore as having a colorful red-banded head. This is the seventh species in the genus, the third species known from Ecuador, and the first new species of Siphlophis since 1940. The results are published in the April 1st issue of the South American Journal of Herpetology.

Philodryas amaru
From Zaher et al. 2014

In a montane grassland high in the Andes Mountains of southern Ecuador, another genus gained its 21st species this year: Philodryas amaru. Known to the Ecuadorian and Brazilian authors since 2005, a small population of these striped racers was formally described in Zootaxa on April 4th this year. The new species resembles Philodryas simonsii in color pattern, but differs noticeably in its hemipenis morphology. "Amaru" means "snake" in Kichwa, and is also the name of a snake deity who influences water and the economy. This diurnal snake lays clutches of 9-13 eggs underground in galleries and under decaying logs, and probably eats frogs and lizards. It is a close relative of the Galapagos racers that I've written about before.

Causus rasmusseni
From Broadley 2014; photo by Paul L. Lloyd

Night adders (genus Causus) are a small and unusual group of vipers found in sub-Saharan Africa. They were once thought to be the most primitive vipers and were placed in their own subfamily, but they are now grouped with the viperines even though they have a plethora of unusual features: platelike head scales, round pupils, a different hinge mechanism for their erectile fangs, incomplete fang canal closure, and elongate venom glands in most species. On April 25th of this year, Don Broadley³ described the first new species of Causus since 1905. He named it Causus rasmusseni after the late Jens Rasmussen, a Dutch expert on African snakes who died in 2005. This species is found only in the watershed between the Congo and Zambezi basins, where it co-occurs with three other species of Causus. Broadley first became aware that there might be a new species of night adder in this region in 1991, when he noticed pale gray C. rhombetaus from northwestern Zambia with black markings and low ventral scale counts. In 2013, someone sent him a picture of one eating a toad (another unusual adaptation that night adders share with several other snakes), which prompted him to look again at the unusual specimens and describe them as a new species. Few molecular data are available for Causus, so this diagnosis is based on morphology alone.

Micrurus potyguaraFrom Pires et al. 2014

Brazil is graced with nearly 400 species of snakes, including 30 of the world's ~80 species of coralsnakes. The morphology of coralsnakes is highly variable, and there are many misidentified specimens in museum collections, so it is often difficult to recognize new species. A group of Brazilian herpetologists working on the tri-colored coralsnakes from the endangered northeastern coastal forests discovered a new species, which they described in the June 5th issue of Zootaxa (if any of these dates are your birthday, then you share a birthday with that of a new species of snake!).

Top: Jaw of Lycodon aulicus
From Jackson & Fritts 2004
Middle: Lycodon zoosvictoriae
From Neang et al. 2014
Bottom: Lycodon cavernicolus
From Grismer et al. 2014

Wolfsnakes (genus Lycodon) are named for their fearsome-looking fang-like anterior maxillary teeth. Unlike the true fangs of vipers, elapids, and atractaspidids, wolfsnake teeth are not grooved or hollow and they have no venom. Instead, their strongly arched upper jaw helps them feed on skinks, whose hard, cylindrical bodies fit snugly into their diastema, or the gap between their anterior and posterior teeth. The wolf-like anterior teeth keep the skink from being squeezed out of the mouth, while the posterior teeth slice through the skink's cycloid scales. At least 16 of the nearly 60 species of Lycodon have been described since the 1990s, including two this June: Lycodon zoosvictoriae from the Cardamom Mountains of southwestern Cambodia, and L. cavernicolus from a limestone cave in peninsular Malaysia. The latter is a cave-adapted species, both specimens of which were found climbing several feet above the cave floor, in total darkness. It's likely that they eat a cave-adapted gecko. Many of the caves in this region are in immediate danger of being quarried for cement before their endemic fauna and flora can be fully documented. Both of these species were also described in Zootaxa, which is a relatively new journal dedicated almost exclusively to rapid publication of new species descriptions, with the stated goal of aiding conservation efforts by circumventing the lengthy delays normally associated with publication of new science. Since its inception in 2001, Zootaxa has become a daily journal that has published nearly one quarter of all new animal taxa and nomenclatural acts in the last five years, including over 400 new species of reptiles and the 7000th species of amphibian.

"Cloudogram" of Crotalus triseriatus species group
showing the new nine-species arrangement
From Bryson et al. 2014

Just three days before the new gecko, a team of scientists from Mexico, the USA, and Canada published a genetic analysis of the Crotalus triseriatus species group, which contains small montane rattlesnakes found in Mexico and the southwestern USA. Although five species were historically recognized within the group, an analysis of seven nuclear genes revealed that there are at least nine species, including two that were previously recognized as subspecies and two more that have not heretofore been formally recognized. The paper described the two new species: Crotalus tlaloci, named for Tláloc, the Aztec god of rain, and Crotalus campbelli, named for herpetologist Jonathan Campbell. The authors of this paper suggest that these rattlesnakes speciated rapidly from a single common ancestor during the uplifting of the Trans-Mexican Volcanic Belt near the end of the Neogene period 2.6 million years ago, which makes sense because they are not very mobile and populations of their common ancestor likely would have become isolated from one another  on various "Sky Islands" of suitable habitat during the genesis of this new mountain range. Many species are endemic to the high-altitude pine-oak forests and grasslands of this region, which has become famous as the overwintering grounds of the Monarch Butterfly.

Chironius diamantina
From Fernandes & Hamdan 2014

Surprise! Just when you thought we were through, at press time the description of four more new species of snake had just been published, all from relatively recent issues of Zootaxa. One is a Brazilian species of Chironius, one of my favorite genera. Chironius diamantina is the 16th species in the genus, which is unusual is having a very low, even number of dorsal scale rows (10 or 12), the central pair of which are strongly keeled, giving the snake a distinctly flat-backed appearance. This species is found in riparian forests along rocky streams in coastal Brazil, not too far south of the new coralsnake (above). Chironius are diurnal and generally eat birds and mammals. Another is a new Asian keelback, Herpetoreas burbrinki, from near the border of China, India, and Burma. which is relatively closely related to the Rhabdophis above. Finally, two new species from the large ground-dwelling Latin American genus Atractus, both small and described from single specimens collected decades ago in Colombia (perhaps they will one day be rediscovered). More new species from both of these groups will likely follow, given the taxonomic untidiness of their genera. [Update: shortly after publication David Salazar-Valenzuela alerted me to the fact that I had missed his description, with colleagues, of a third new Atractus from the cloud forests of northern Ecuador earlier this year, in the journal Herpetologica. They mention that some of the specimens were collected from under logs alongside an undescribed species of slender blindsnake of the genus Trilepida, so it seems we are at 3,500 this year without a doubt!] [[Update II: It seems I missed more than I thought - a new species of Trimeresurus from Sumatra was described in September from specimens collected in 1899, and a new Ninia from Trinidad was described in August from a 1988 specimen.]]

In addition to these 15 species, there are a couple of species of snake which were described long ago but that were revalidated recently, including several scolecophidians (Typhlops silus, first described in 1959; Afrotyphlops angeli, first described in 1952; and Letheobia acutirostrata, first described in 1916) and a rattlesnake (Crotalus armstrongi, originally described as a subspecies in 1979 and elevated by the same group that described C. tlaloci and C. campbelli). These are typically announced with less fanfare than the truly new descriptions that I've highlighted above.

Although it's actually been the slowest year for new snakes since 1997⁴, we have 15 new snakes this year, bringing snakes to a total of 3,499 (and 2014 isn't over yet!). We could make it to 3,500 snakes in the same year that we hit 10,000 reptiles. I think these milestones in taxonomy emphasize the importance of reptiles and how much we have left to learn about them. I doubt that the pace of new species descriptions will slow down anytime soon, as experts estimate that less than 15% of the species on Earth have yet been described. Increasingly, reptiles, and snakes in particular, are becoming poster-children for biodiversity and conservation, a welcome change from their history of being overlooked and maligned. Soon, we will have high-quality global range maps for all species of reptiles, an achievement reached some time ago by amphibians, mammals, and birds, which will enable their incorporation into global assessments of vertebrate diversity and conservation planning. It's an exciting time.

For a complete list of all 24 snake species eventually described in 2014, click here.

ACKNOWLEDGMENTS

Thanks to Peter Uetz at The Reptile Database for sharing with me some inside information, and to the authors of these papers for their photos.

REFERENCES

Newspaper clipping from 10 January 1960
showing Broadley with his amputated finger.
You can see more at the finger's Facebook page
or listen to Broadley describe the experience here.

Angarita-Sierra, T. 2014. Hemipenial Morphology in the Semifossorial Snakes of the Genus Ninia and a New Species from Trinidad, West Indies (Serpentes: Dipsadidae). South American Journal of Herpetology 9:114-130 <link>

Broadley, D. G. 2014. A new species of Causus Lichtenstein from the Congo/Zambezi watershed in north-western Zambia (Reptilia: Squamata: Viperidae). Arnoldia Zimbabwe 10:341-350 <link>

Bryson, R. J., C. W. Linkem, M. E. Dorcas, A. Lathrop, J. M. Jones, J. Alvarado-Diaz, C. I. Grunwald, and R. W. Murphy. 2014. Multilocus species delimitation in the Crotalus triseriatus species group (Serpentes: Viperidae: Crotalinae), with the description of two new species. Zootaxa 3826:475-496 <link>

Cope, E. D. 1895. The classification of the Ophidia. Transactions of the American Philosophical Society 18:186-219 <link>

Dowling, H. G. 1967. Hemipenes and other characters in colubrid classification. Herpetologica 23:138–142 <link>

Grismer, L. L., E. S. H. Quah, S. Anuar, M. A. Muin, P. L. Wood Jr, and S. A. M. Nor. 2014. A diminutive new species of cave-dwelling Wolf Snake (Colubridae: Lycodon Boie, 1826) from Peninsular Malaysia. Zootaxa 3815:51-67 <link>

Guo, P., Q. Liu, L. Zhang, J. X. Li, Y. Huang, and R. A. Pyron. 2014. A taxonomic revision of the Asian keelback snakes, genus Amphiesma (Serpentes: Colubridae: Natricinae), with description of a new species. Zootaxa 3873:425-440 <link>

Fernandes, D. and B. Hamdan. 2014. A new species of Chironius Fitzinger, 1826 from the state of Bahia, Northeastern Brazil (Serpentes: Colubridae). Zootaxa 3881:563-575 <link>

Trimeresurus gunaleni
From Vogel et al 2014

Jackson, K. and T. H. Fritts. 2004. Dentitional specialisations for durophagy in the Common Wolf snake, Lycodon aulicus capucinus. Amphibia-Reptilia 25:247-254 <link>

Köhler, G. and M. Kieckbusch. 2014. Two new species of Atractus from Colombia (Reptilia, Squamata, Dipsadidae). Zootaxa 3872:291-300 <link>

Linnaeus, C. 1758. Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata. [10th ed.]. Laurentii Salvii, Holmiae, Stockholm, Sweden <link>

Myers, C. W. and S. B. McDowell. 2014. New Taxa and Cryptic Species of Neotropical Snakes (Xenodontinae), with Commentary on Hemipenes as Generic and Specific Characters. Bulletin of the American Museum of Natural History 385:1-112 <link>

Neang, T., T. Hartmann, S. Hun, N. J. Souter, and N. M. Furey. 2014. A new species of wolf snake (Colubridae: Lycodon Fitzinger, 1826) from Phnom Samkos Wildlife Sanctuary, Cardamom Mountains, southwest Cambodia. Zootaxa 3814:68-80 <link>

Pires, M. G., N. J. da Silva Jr., D. T. Feitosa, A. L. d. C. Prudente, G. A. P. Filho, and H. Zaher. 2014. A new species of triadal coral snake of the genus Micrurus Wagler, 1824 (Serpentes: Elapidae) from northeastern Brazil. Zootaxa 3811:569-585 <link>

Atractus savagei
From Salazar-Valenzuela et al. 2014

Salazar-Valenzuela, D., O. Torres-Carvajal, and P. Passos. 2014. A New Species of Atractus (Serpentes: Dipsadidae) from the Andes of Ecuador. Herpetologica 70:350-363 <link>

Schneider, N., T. Q. Nguyen, M. D. Le, L. Nophaseud, M. Bonkowski, and T. Ziegler. 2014. A new species of Cyrtodactylus (Squamata: Gekkonidae) from the karst forest of northern Laos. Zootaxa 3835:80-97 <link>

Sheehy, C. M., M. H. Yánez-Muñoz, J. H. Valencia, and E. N. Smith. 2014. A new species of Siphlophis (Serpentes: Dipsadidae: Xenodontinae) from the eastern Andean slopes of Ecuador. South American Journal of Herpetology 9:30-45 <link>

Teynié, A., A. Lottier, P. David, T. Q. Nguyen, and G. Vogel. 2014. A new species of the genus Opisthotropis Günther, 1872 from northern Laos (Squamata: Natricidae). Zootaxa 3774:165-183 <link>

Uetz, P. 2010. The original descriptions of reptiles. Zootaxa 2334:59-68 <link>

Vogel, G., P. David, and I. Sidik. 2014. On Trimeresurus sumatranus (Raffles, 1822), with the designation of a neotype and the description of a new species of pitviper from Sumatra (Squamata: Viperidae: Crotalinae). Amphibian and Reptile Conservation 8:1–29 <link>

Zaher, H., J. C. Arredondo, J. H. Valencia, E. Arbeláez, M. T. Rodrigues, and M. Altamirano-Benavides. 2014. A new Andean species of Philodryas (Dipsadidae, Xenodontinae) from Ecuador. Zootaxa 3785:469–480 <link>

Zhu, G.-X., Y.-Y. Wang, H. Takeuchi, and E.-M. Zhao. 2014. A new species of the genus Rhabdophis Fitzinger, 1843 (Squamata: Colubridae) from Guangdong Province, southern China. Zootaxa 3765:469-481 <link>

Life is Short, but Snakes are Long by Andrew M. Durso is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

Snakes long-lost

Click here to read this post in Spanish!
Haga clic aquí para leer este blog en español!

Alternate title suggested by Mike Pingleton: Not all who slither are lost

Clarión Nightsnake (Hypsiglena unaocularis)
Photograph from Mulcahy et al. 2014

Just over one year ago, a team of scientists from the Smithsonian and the Red de Interacciones Multitróficas rediscovered a species of nightsnake (genus Hypsiglena) on remote Clarión Island in the eastern Pacific Ocean, over 400 miles southwest of Cabo San Lucas. Called the Clarión Nightsnake (Hypsiglena unaocularus), it was originally discovered by the renowned American naturalist William Beebe in 1936, during a nocturnal sea turtle nesting survey. Because Clarión Island is only accessible via military escort, biologists have not visited the island frequently since Beebe's time, and in 1955 herpetologist Bayard Brattstrom suggested that perhaps Beebe's locality information had been an error, since only a single specimen existed and several other Clarión Island expeditions had not turned up another. However, the type specimen collected by Beebe, resting in the herpetology collection of New York's American Museum of Natural History, was sufficiently distinct from any other Hypsiglena specimen that it prompted herp phylogeographer Dan Mulcahy to reexamine Beebe's book and field notes, which contained a pretty clear description of the circumstances under which Beebe found the snake:

“We walked on, flashing the light all around. Not far from the water on the black lava 

I saw a small dark brown snake. It seemed to be unlike the one I had found in daylight, 

having lines of black spots on the body, so I picked it up and cached it in my shirt.” 

(p. 282 of Zaca Venture)

Location of Clarión Is.
From Mulcahy et al. 2014
Click to enlarge

As their name implies, Nightsnakes mostly come out at night (although I found one in southern Utah at about 9:30 in the morning a few weeks ago), and even then they are normally only active under certain conditions - in particular, they prefer to be active when there is not much moonlight, such as on cloudy nights or when the moon is new. Even if one is specifically searching for Nightsnakes, they can be difficult to find. Combined with their generally secretive nature, this could explain the failure of several Clarión Island expeditions to find the Clarión Nightsnake - until Mulcahy's expedition in May of 2013, which found 11 individuals in 15 days. Using phylogenetics, they determined that the Clarión Nightsnake is most closely related to the Santa Catalina Nightsnake (H. catalinae), which is found on Santa Catalina Island in the Gulf of California (which is not the same as the well-known Santa Catalina Island off of the US state of California). Nightsnakes are found all around the shoreline of the Gulf of California, and they are obviously exceptional over-water dispersers, because they occur on many of the islands in that region as well.

This remarkable story of rediscovery is a testament to the kind of attention to detail that it takes to be a good natural historian, but it's not the only species of snake that has been rediscovered many years after its initial description. Here are a few others:

Angel’s Stream Snake (Paratapinophis praemaxillaris)
Photograph from Murphy et al. 2008

Angel’s Stream Snake (Paratapinophis praemaxillaris) was described from two newborn specimens from northern Laos in 1929. At that time it was placed into a new genus because of an unusual process on its nose, but a few years later it was moved into the cosmopolitan genus Opisthotropis. Two more specimens were collected in the 1980s, but it wasn't until 2008, when five adult specimens were collected from a pool at the base of a waterfall on the Nan River in northern Thailand, that it became clear that the nose structure was actually an egg tooth, a structure normally lost a few days after hatching. At that time, Paratapinophis was placed back into its own genus because of several other formerly-overlooked unique features, including sexually dimorphic color, pattern, and scale ornamentation. Like most other natricines, this species eats fishes.

Chersodromus rubriventris
Photograph from Ramírez-Bautista et al. 2013

Chersodromus rubriventris, the Redbelly Earth Runner, was discovered in a cloud forest in San Luis Potosí, Mexico, just after the end of World War II and described a few years later by American herpetologist and spy Edward H. Taylor, who also used his biology as a cover for work in the Philippines, Russia, and Sri Lanka during both world wars. Two other specimens, one from the late 1960s and the other from the early 1980s, were known, but in 2013, a team of herpetologists from the Universidad Autónoma del Estado de Hidalgo found three individuals in a cloud forest in nearby Hidalgo, doubling the number of specimens and photographing the snake alive for the first time. Stomach contents included beetle larvae and ants, both of which are unusual prey for a dipsadid snake.

Atractus wagleri
Photograph from Passos & Arredondo 2009

The genus Atractus, a group of burrowing snakes found from Panama to Argentina, is the most diverse alethinophidian snake genus, with over 130 species, most of which are only known from a few specimens. Recently Paulo Passos of the Brazilian National Museum matched up several previously mis- or unidentified Atractus specimens in South American museums with their species, constituting rediscoveries of sorts. For example, Wagler's Ground Snake (Atractus wagleri) was described in 1945 from a single specimen from western Colombia, and that specimen was lost in a fire in 1948. In 2009 Passos located three additional specimens of this poorly known snake in museums in Colombia. Another species, the Modest Ground Snake (Atractus modestus), was described in 1894 by the great Belgian zoologist George Boulenger, from a single specimen from western Ecuador. In 2007 Passos located more specimens in Ecuadorian museums, expanding the range of the species across most of the country. Although species of Atractus are seemingly quite rare, occurring at high elevations and having secretive fossorial habitats, a large number of Atractus specimens remain misidentified or unidentified in herpetological collections, so our knowledge of these snakes stands to improve dramatically as these are examined and described.

Argus Snail Sucker (Sibon argus)

The Lichen-coloured or Argus Snail Sucker (Sibon argus) is an extremely slender arboreal dipsadine snake with eye-like ("ocellate") spots. It was originally described from a single specimen from southeastern Costa Rica in 1876, by renowned paleontologist Edward Drinker Cope (who feuded with O.C. Marsh in the "Bone Wars" over who could discover more dinosaurs, the subject of an upcoming film starring Steve Carrell as Cope). The validity of the species was uncertain because of the subsequent description of other gracile snakes with ocellated patterns from the same region. In his classic revision of Neotropical snail- and slug-eating snakes, James Peters suggested that Cope's specimen might be aberrant, or perhaps that it represented one half of a species with strong sexual dimorphism (which is rare in snakes), because the only known S. argus specimen  was a male, and another species, Sibon longifrenis, was known at the time from just two specimens, both females. Males and females of the same species had been described as separate species before. Ultimately, Peters decided that the two species were probably different, and he was proven right in 1992, when tropical herpetologist Jay Savage was preparing his opus on Costa Rican herpetofauna. Savage discovered both male and female specimens that best matched Cope's 1876 S. argus in the collections of the University of Kansas and the Universidad de Costa Rica. The snakes had been collected in evergreen forests in Panama and Costa Rica, near the type locality of S. argus. With Roy McDiarmid, Savage redescribed the species, which has become much more well-known since. A recent study by Julie Ray and colleagues documented a more diverse diet for this species than previously expected, including other gooey prey such as oligochaete worms and frog eggs. Unfortunately for Sibon argus, both of these prey types are in decline in the neotropics, the worms due to overcollection of their bromeliad homes for horticulture, and the amphibians due to the devastating effects of the amphibian chytrid fungus Batrachochytrium dendrobatidis.

Brygophis coulangesi
Photograph from Andreone & Raxworthy 1998

Other examples of rediscovered snakes abound. The Uluguru Worm Snake (Letheobia uluguruensis) was described from four specimens collected in 1926 from the Uluguru Mountains of eastern Tanzania, a mountain range with dozens of endemic species, and was not seen again until 2004, when four were dug up by local people employed by a group of herpetologists from the London Natural History Museum and the University of Glasgow to search for caecilians. Another blindsnake, Typhlops tasymicris, was rediscovered on Union Island, St. Vincent and the Grenadines, in 2010. An entire genus of blindsnake, Xenotyphlops, was rediscovered in Madagascar, in 2007, 102 years after it's description. A rare sea snake, Hydrophis parviceps, was originally collected by the Danish research vessel Dana and described in 1935 and was seen again only once in 1960 until three turned up in fisheries bycatch off of Vietnam in 2001. Another species of rare sea snake, H. bituberculatus, was rediscovered off Sri Lanka in the late 1980s, over 100 years after the first one was collected (although the fishermen who collected the specimen were so secretive that they refused to divulge the location). One of the rarest snakes in Madagascar, a slow-moving reddish-orange species called Brygophis coulangesi, was first collected in 1968, when one fell from a tree and vomited up a chameleon, with a second specimen found on a cloudy, rainy night during a rain forest survey in 1998, over 300 miles to the north of the first. A second specimen of another Malagasy lamprophiid, Alluaudina mocquardi, was discovered in a pitch-black cave in northern Madagascar in 1982, 50 years after the first was found in a different cave nearby. I don't think any more have been found since, so this one should be getting ready to be rediscovered again soon (edit: City University of New York snake biologist Frank Burbrink informed me that on his recent trip to Madagascar they turned up an Alluaudina mocquardi in tsingy rock at Ankarana - see photo here)!

March 2010 Herp. Review cover
featuring Crotalus lannomi

A high-profile rediscovery graced the cover of the March 2010 issue of the journal Herpetological Review, which featured a photograph of a long-sought-after species of rattlesnake, the Autlán Long-tailed Rattlesnake (Crotalus lannomi). Discovered in the summer of 1966 by Joseph Lannom, C. lannomi became sort of a “holy grail” of rattlesnakes in the decades that followed, as numerous herpetologists ventured into the mountains of western Jalisco in search of it. They were stymied by heavy fog and dangerous flooding, roads with treacherous curves and highway robberies, and drug-related violence. In 2008, five specimens of C. lannomi were found in the foothills of Colima, roughly 50 km from the type locality in Jalisco, in some of Mexico's most pristine forest habitat.

Although most of this was new to me, I've actually written about a different rediscovered viper before, the Spider-tailed Adder (Pseoducerastes urarachnoides) of Iran, which was discovered in 1968 and was at first thought to have either a tumor, a congenital defect, or a growth caused by a parasite, or maybe a spider clinging to its tail (turns out its tail is modified into a lure to attract spider-eating birds). Also, in one of my first articles, I wrote about the South Florida Rainbow Snake (Farancia erytrogramma seminola), described by Wilfred T. Neill in 1964 from Fisheating Creek in Glades County near Lake Okeechobee, Florida, and presumed extinct, never seen again since. To the best of my knowledge this subspecies has yet to be rediscovered, despite a $500 reward from the Center for Snake Conservation and Center for Biological Diversity. (Edit: a diligent reader reminded me that I also wrote about another snake that hasn't been seen since 1975 in one of my earliest articles, the Round Island Burrowing Boa, Bolyeria multocarinata).

Undoubtedly there are numerous snake species left to be discovered and rediscovered, and in many cases almost nobody's out there looking. The Reptile Database has predicted that the total number of described reptile species will surpass 10,000 in 2014, and that non-avian reptiles will perhaps eclipse birds in diversity soon after that. With snakes currently at 3,466, representing just over one third of reptiles, maybe you will be the next to rediscover a snake thought lost!

ACKNOWLEDGMENTS

Thanks to Dan Mulcahy and Don Filipiak for the use of their photographs.

REFERENCES

Andreone, F. and C. Raxworthy. 1998. The colubrid snake Brygophis coulangesi (Domergue 1988) rediscovered in north-eastern Madagascar. Tropical Zoology 11:249-257 <link>

Beebe, CW. 1938. Zaca Venture. Harcourt, Brace and Co. Inc., New York <link>

Cope, E. D. 1875. On the batrachia and reptilia of Costa Rica : With notes on the herpetology and ichthyology of Nicaragua and Peru. Journal of the Academy of Natural Sciences Philadelphia 2:93-157 <link>

Gower, D. J., S. P. Loader, and M. Wilkinson. 2004. Assessing the conservation status of soil‐dwelling vertebrates: Insights from the rediscovery of Typhlops uluguruensis (Reptilia: Serpentes: Typhlopidae). Systematics and Biodiversity 2:79-82 <link>

Lanza, B. 1990. Rediscovery of the Malagasy colubrid snake Alluaudina mocquardi Angel 1939. Tropical Zoology 3:219-223 <link>

Mulcahy, D. G., J. E. Martínez-Gómez, G. Aguirre-León, J. A. Cervantes-Pasqualli, and G. R. Zug. 2014. Rediscovery of an endemic vertebrate from the remote Islas Revillagigedo in the eastern Pacific Ocean: The Clarión Nightsnake lost and found. PLoS ONE 9:e97682 <link>

Mulcahy, D. G. and J. R. Macey. 2009. Vicariance and dispersal form a ring distribution in nightsnakes around the Gulf of California. Molecular Phylogenetics and Evolution 53:537-546 <link>

Murphy, J. C., T. Chan-Ard, S. Mekchai, M. Cota, and H. K. Voris. 2008. The rediscovery of Angel’s Stream Snake, Paratapinophis praemaxillaris Angel, 1929 (Reptilia: Serpentes: Natricidae). The Natural History Journal of Chulalongkorn University 8:169-183 <link>

Passos, P. and J. C. Arredondo. 2009. Rediscovery and redescription of the Andean earth-snake Atractus wagleri (Reptilia: Serpentes: Colubridae). Zootaxa 1969:59-68 <link>

Passos, P., D. F. Cisneros-Heredia, and D. Salazar-V. 2007. Rediscovery and redescription of the rare Andean snake Atractus modestus. The Herpetological Journal 17:1-6 <link>

Peters, J. A. 1960. The snakes of the subfamily Dipsadinae. Miscellaneous Publications of the Museum of Zoology, University of Michigan 114:1-228 <link>

Ramírez-Bautista, A., C. Berriozabal-Islas, R. Cruz-Elizalde, U. Hernández-Salinas, and L. Badillo-Saldaña. 2013. Rediscovery of the snake Chersodromus rubriventris (Squamata: Colubridae) in cloud forest of the Sierra Madre Oriental, México. Western North American Naturalist 73:392-398 <link>

Rasmussen, A. R. 1992. Rediscovery and redescription of Hydrophis bituberculatus Peters, 1872 (Serpentes: Hydrophidae). Herpetologica 48:85-97 <link>

Rasmussen, A. R., J. Elmberg, K. L. Sanders, and P. Gravlund. 2012. Rediscovery of the rare sea snake Hydrophis parviceps Smith 1935: identification and conservation status. Copeia 2012:276-282 <link>

Ray, J. M., C. E. Montgomery, H. K. Mahon, A. H. Savitzky, and K. R. Lips. 2012. Goo-eaters: Diets of the Neotropical snakes Dipsas and Sibon in central Panama. Copeia 2:197-202 <link>

Reyes-Velasco, J., C. I. Grünwald, J. M. Jones, and G. N. Weatherman. 2010. Rediscovery of the rare Autlán Long-tailed Rattlesnake, Crotalus lannomi. Herpetological Review 41:19-25 <link>

Rodríguez, M. J. R., E. J. Bentz, D. P. Scantlebury, R. R. John, D. P. Quinn, J. S. Parmerlee Jr, R. W. Henderson, and R. Powell. 2011. Rediscovery of the Grenada Bank endemic Typhlops tasymicris (Squamata: Typhlopidae). Journal of Herpetology 45:167-168 <link>

Savage, J. M. and R. W. McDiarmid. 1992. Rediscovery of the Central American colubrid snake, Sibon argus, with comments on related species from the region. Copeia 1992:421-432 <link>

Taylor, E. H. 1949. A preliminary account of the herpetology of the state of San Luis Potosí, Mexico. University of Kansas Science Bulletin 33:169-215 <link>

Wallach, V., V. Mercurio, and F. Andreone. 2007. Rediscovery of the enigmatic blind snake genus Xenotyphlops in northern Madagascar, with description of a new species (Serpentes: Typhlopidae). Zootaxa 1402:59-68 <link>

Weaver, R. E. 2010. Activity Patterns of the Desert Nightsnake (Hypsiglena chlorophaea). The Southwestern Naturalist 55:172-178 <link>

Life is Short, but Snakes are Long by Andrew M. Durso is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.