Xenophidion

Name

Xenophidion (Fitzinger, 1843)

Vernacular names
English: Spinejaw Snakes

Xenophidion is a genus of snakes first described in 1995, and the only genus of the monotypic family Xenophidiidae.[1] Commonly referred to as spinejaw snakes, this genus is found in Borneo and peninsular Malaysia.

Morphology and classification

This genus is taxonomically and phylogenetically challenging to classify, as these snakes possess several morphological traits that distinguish them from all other snake species; head scales with numerous sensory papillae, large prefrontal scales, and an upper jaw which has a spiny palatine process. They also lack any pelvic girdle vestiges, a left lung, or a coronoid bone.[2] In 2004, cytochrome b sequencing suggested a sister relationship of Xenophidion to Bolyeriidae from Mauritius.[3] Similar to Boyleriidae, spinejaw snakes have a jointed maxilla.
Diet, reproduction, and habitat

Very little is known about this genus. Specimen dissection has revealed the presence of a partially digested skink and an oviparous mode of reproduction, but male specimens have not yet been identified.[4] They are likely fossorial and may be under severe threat from palm oil agriculture.
Species

Xenophidion acanthognathus Günther & Manthey, 1995
Xenophidion schaeferi Günther & Manthey, 1995

References

Genus Xenophidion at The Reptile Database.
Wallach, Van; Günther, Rainer (1998). "Visceral anatomy of the Malaysian snake genus Xenophidion, including a cladistic analysis and allocation to a new family". Amphibia-Reptilia. 19 (4): 385–405. doi:10.1163/156853898X00052.
Lawson, R.; Slowinski, J. B.; Burbrink, F. T. (2004). "A molecular approach to discerning the phylogenetic placement of the enigmatic snake Xenophidion schaeferi among the Alethinophidia". Journal of Zoology. 263 (3): 285–294. CiteSeerX 10.1.1.504.6967. doi:10.1017/S0952836904005278.
Xenophidion: The Snake with the Mystery Penis. snakesarelong.blogspot.com (28 September 2016)