Najash

Najash Temporal range: Late Cretaceous, 90 Ma PreЄ Є O S D C P T J K Pg N ↓
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Squamata
Suborder:	Serpentes
Genus:	Najash
Species:	N. rionegrina
Binomial name
Najash rionegrina Apesteguía & Zaher, 2006

Paleontology portal

Najash is an extinct genus of basal snake. Like a number of other Cretaceous snakes (see below), it had two hind-limbs. The fossils were found in a land-based deposit, and the robust backbone vertebrae and rear legs of the snake were adapted to a burrowing, subterranean environment. This is significant, as it suggests that snakes had a terrestrial origin, and presents new evidence in the complicated sequences that led to limb reduction and loss as snakes developed from their lizard ancestors.

The snake was no more than 1.5 meters (5 feet) long, and lived during the Late Cretaceous period (ca. 90 million years ago) in what is now the Rio Negro province (hence its specific name rionegrina) of Patagonia, Argentina.

This burrowing creature had not lost its sacrum, the pelvic bone composed of several fused vertebrae, nor its pelvic girdle which are absent in modern snakes, and in all other known fossil snakes as well^[1].

This discovery does not support the hypothesis, first offered by the nineteenth-century paleontologist Edward Drinker Cope, that snakes share a common marine ancestry with mosasaurs. The marine origin hypothesis received new impetus with the discovery in the 1990s of basal snakes with vestigial limbs in marine sediments in Lebanon.

The generic name comes from the biblical legged snake of Genesis, Nahash, who tempted Adam and Eve to eat from a forbidden fruit tree.

Footnotes

1. ^ Other known fossil snakes with developed hindlimbs, Haasiophis, Pachyrhachis and Eupodophis—all found in marine environments— all lack a sacral region.

References

• Apesteguía, Sebastián; Hussam Zaher (April 2006). "A Cretaceous terrestrial snake with robust hindlimbs and a sacrum". Nature 440 (7087): 1037–1040. doi:10.1038/nature04413. PMID 16625194. http://www.nature.com/nature/journal/v440/n7087/edsumm/e060420-11.html. Retrieved 2006-04-19. 
• Pharyngula: "Najash rionergina, a snake with legs" Presents abstract of the Nature report.