Viper-mimicking snake from Asia is a unique branch in the reptile evolutionary tree
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MOCK VIPERS NOT ONLY LOOK LIKE TREE-DWELLING VIPERS BUT ALSO ACT LIKE THEM. INTRIGUINGLY, THEY HAVE A FAKE ‘FANG’ IN THE FRONT OF THEIR MOUTH, WHICH BEFOOLS A PREDATOR INTO THINKING THAT THEY POSSESS VENOM FANGS DURING AN OPEN-MOUTHED THREAT DISPLAY. HOWEVER, THERE IS ALSO AN ACTUAL FANG IN THE BACK OF THE JAW, WHICH CARRIES A WEAK VENOM EFFECTIVE ONLY ON THEIR LIZARD PREY.
view moreCREDIT: RUSHEN JAIHAN
The evolutionary history of the mock viper has been solved by an international research team led by scientists from the University of Helsinki. This mildly venomous viper look-alike represents a totally unique branch in the tree of life of snakes.
The evolutionary history of the mock viper, a mildly venomous, widely distributed Asian snake that mimics highly venomous vipers for self-defence, has been solved. The mock viper represents a completely unique branch in the tree of life of snakes, and hence, it has been allocated into its own new family named Psammodynastidae.
This small, feisty snake has long presented a puzzle to evolutionary scientists due to its unresolved evolutionary history. To solve the puzzle, the researchers analysed DNA sequences of over 4500 genes and several dozen high-resolution micro-computed tomographic scans.
“Mock vipers are part of the superfamily Elapoidea, a major group of snakes to which one-fifth of global serpent diversity belongs. Evolutionary diversification within this superfamily happened very rapidly approximately 50 million years ago. Rapid evolutionary diversifications are probably the most challenging evolutionary scenario for a geneticist or evolutionary biologist to resolve”, says the lead researcher Sunandan Das from the University of Helsinki.
Mock vipers not only look like tree-dwelling vipers but also act like them. Intriguingly, they have a fake ‘fang’ in the front of their mouth, which befools a predator into thinking that they possess venom fangs during an open-mouthed threat display. However, there is also an actual fang in the back of the jaw, which carries a weak venom effective only on their lizard prey. The Elapoidea superfamily has multiple snake families with various types of venom and fangs, for example cobras and mambas.
Another completely new family-level lineage, Micrelapidae, within Elapoidea was discovered in 2023 by Sunandan and Professor Juha Merilä.
“The discovery of a new family of any vertebrate animals is surprisingly rare, an almost once-in-a-century phenomenon. This is a lifetime achievement for an evolutionary biologist. You rarely, if ever, see descriptions of whole new families of well-studied vertebrate animals anymore.’’ says Sunandan.
The inference of the phylogenetic position of mock vipers, along with that of other elapoid snakes, will pave the way for a much better understanding of snake venom fang origin and evolution. Long, unique branches in the phylogeny, like that of mock vipers, contains a high degree of evolutionary distinctiveness, an index used by biologists for prioritising conservation. Hence, reinstating the mock viper or Psammodynastes into its own ‘dynasty’ also serves an important conservation goal.
JOURNAL
Scientific Reports
SUBJECT OF RESEARCH
Animals
ARTICLE TITLE
Phylogenomics of Psammodynastes and Buhoma (Elapoidea: Serpentes), with the description of a new Asian snake family
The missing puzzle piece: A striking new snake species from the Arabian Peninsula
PENSOFT PUBLISHERS
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RHYNCHOCALAMUS HEJAZICUS PICTURED IN LIFE.
view moreCREDIT: FULVIO LICATA
Researchers have discovered a new distinctive and secretive snake species in the Hejaz region of Saudi Arabia.
Rhynchocalamus hejazicus is a small snake bearing a black collar and reddish colouration, distinguishing it from its closest relatives. A uniformly black ‘melanistic morphotype’ of the species has also been discovered.
The new species is widely distributed and fills much of the existing distribution gap between the Levant and the coastal regions of Yemen and Oman for the genus Rhynchocalamus.
An international team led by scientists from the Centro de Investigação em Biodiversidade e Recursos Genéticos (CIBIO), Portugal, and Charles University, Czech Republic, published their discovery in Zoosystematics and Evolution, an open-access journal published by Pensoft on behalf of Museum für Naturkunde Berlin.
Rhynchocalamus hejazicus inhabits sandy and stony soils with varying vegetation cover and can be found in habitats disturbed by humans, suggesting that the species should not be categorised as threatened according to IUCN criteria.
Little is known about the species’ natural history and behaviour, and further monitoring and conservation efforts are necessary to better understand its ecological dynamics and natural history. However, it appears that Rhynchocalamus hejazicus has mainly nocturnal activity as all individuals were encountered active at night.
"The discovery of a new species of snake widespread in the central-western regions of Saudi Arabia is surprising and gives rise to the hope that more undiscovered species might be present in the Kingdom" the authors say.
Most of the observations of the new species are the result of intense sampling efforts in a vast area around the ancient Arabic oasis city of AlUla, fostered by the Royal Commission for AlUla, Saudi Arabia, which is pushing forward scientific activities and explorations to promote conservation in the region. The intensifying of field studies in Saudi Arabia in the last years is leading to fruitful collaborations and such important findings as this study, to which many experts from multiple teams have contributed significantly.
The discovery of such a distinctive snake highlights the existing gap in the description of rare and secretive species, and the need to enhance sampling efforts and monitoring strategies to fully capture species diversity in unexplored areas.
Original source
Licata F, Pola L, Šmíd J, Ibrahim AA, Liz AV, Santos B, Patkó L, Abdulkareem A, Gonçalves DV, AlShammari AM, Busais S, Egan DM, Ramalho RMO, Smithson J, Brito JC (2024) The missing piece of the puzzle: A new and widespread species of the genus Rhynchocalamus Günther, 1864 (Squamata, Colubridae) from the Arabian Peninsula. Zoosystematics and Evolution 100(2): 691-704. https://doi.org/10.3897/zse.100.123441
Black ‘melanistic morphotype’ of Rhynchocalamus hejazicus pictured in life.
CREDIT
Fulvio Licata
Rhynchocalamus hejazicus pictured in life.
CREDIT
Fulvio Licata
Habitats of Rhynchocalamus hejazicus: Top: Shaaran NR, AlUla County, Medina Province, KSA; bottom left: Wadi Al-Azraq, Jabal Salma, Hail Province, KSA; bottom right: Harrat Khaybar, Hail Province, KSA.
CREDIT
Fulvio Licata and Adel A. Ibrahim
JOURNAL
Zoosystematics and Evolution
ARTICLE TITLE
The missing piece of the puzzle: A new and widespread species of the genus Rhynchocalamus Günther, 1864 (Squamata, Colubridae) from the Arabian Peninsula
ARTICLE PUBLICATION DATE
30-May-2024
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