Discovery of a Trace Fossil Containing the Remains of Minuscule Squamates: Evidence in Support of the Lizard to Snake Hypothesis

Abstract

John Kelly Smith

The smallest known saurian reported to date is Oculudentavis nanus, a tiny lizard-like animal from the Late Cretaceous (100.5 to 66 Ma) which measure ~5 cm in length. The smallest known snake is Tetrapodophis amplectus from the early Cretaceous period (145 to 100.5 Ma) which measures ~20 cm in length. I now report the finding of a ~0.5 – 0.6 mm long limbed squamate with a spade-like tail and features that otherwise resemble those of extant Geckos colonizing the dorsal surface of a trace fossil from Hamblen County, Tennessee. Also found are three 0.4 - 0.6 mm long saurian-like juveniles undergoing body elongation and limb reduction and the remains of a tiny snake-like squamate measuring 1.0 mm snout-to-vent and 7.0 mm snout-to-tail, findings in keeping with the lizard-to-snake hypothesis. The circumstances leading to the miniaturization of these squamates is unknown but may represent the metabolic and reproductive advantages of smallness.

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