May 3, 2006 | David F. Coppedge

Limbed Snakes Initiate Evolutionary Quandary

Researchers have discovered the fossil of a snake with a pelvis and functioning legs in Rio Negro, Argentina.  Sebastian Apesteguía (Argentine Museum of Natural Science) says Najash rionegrina is not the oldest snake discovered; marine snakes have been discovered in North America as well as Eastern Europe.  However, Najash rionegrina has been considered the earliest limbed snake found in terrestrial sediment.  According to Nicholas Bakalar (National Geographic News):1,2

Early snakes, the theory’s supporters say, are closely related to scolecophidians, a living group of primitive land snakes that still have vestigial pelvic regions.  But proponents of a watery origin believe that snakes most likely evolved from extinct marine reptiles called mosasaurs, powerful swimmers that spent their entire lives in the ocean.  “Snakes probably evolved during the Jurassic—150 million years ago,” Apesteguía said, “but there are no fossils.”  During the early Cretaceous—120 million years ago—they exploded [into] several forms, including some terrestrial like Najash, “…and some aquatic.  The fossil record shows that terrestrial and aquatic snakes both existed by the mid-Cretaceous—about 95 million years ago—leaving researchers unsure about which type evolved first.”  The question, Apesteguía said, is, “Which is more primitive, the terrestrial Najash or the most primitive water snakes, a group called pachyophids?”  He points to evidence that marine snakes are less primitive: Their skull bones suggest that they could expand their mouths to ingest larger prey—a characteristic of modern snakes.  The marine snakes, Apesteguía concludes, “are ancient versions of modern snakes, not really primitive.”

1“Snakes Evolved on Land, New Fossil Find Suggests,” National Geographic News, Accessed April 23, 2006.
2“Snake Ancestors Lost Limbs on Land, Study Says,” National Geographic News, Accessed April 23, 2006.

It is not a surprise that evolutionists cannot decide between an aquatic or terrestrial origin for snakes.  Although researchers have realized that marine and land snakes existed at the same time, they have only accepted this coexistence to an extent.  In fact, Sebastian Apesteguía has stated that the evidence of transition fossils does not exist.  As a result, Apesteguía and other researchers, including Hassum Zaher (University of Sao Paulo in Brazil), are uncertain about the position of either species on the evolutionary chain.  Zaher suggested that limbed snakes are related to pythons and boas and not marine snakes.  This conflicts with Apesteguía’s allusion to an aquatic origin.  The discovery of Najash will only rekindled the flame of controversy as evolutionists attempt to avoid another kink in their chain.
—Courtney N.

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