Predation upon Hatchling Dinosaurs by a New Snake from the Late Cretaceous of India

Abstract

A new snake from Upper Cretaceous rocks in India is found with hatchling sauropod dinosaurs, demonstrating that large, gape-limited snakes were probably capable of taking in moderate-sized vertebrate prey.

The oldest known snakes from the Middle Jurassic-Lower Cretaceous provide insights on snake evolution

“…4b). The new data, and the results of our analysis of snake phylogeny (see also Supplementary Figs 24 and 25), agree with previous ingroup analyses of fossil snakes 3,4,8,[26][27][28]31 that hypothesized that the most basal snakes are not the extant scolecophidians 7,32 . The new early snakes add to those hypotheses by extending the fossil record of snakes by 70 million years (Fig.…”

“…1n). Such a scenario finds support based on the similarities of their cranial features to those of Dinilysia 10,11 and later madtsoiids 22,[26][27][28] (Fig. 2a-p), which certainly appear to be restricted to Gondwana continents during the Mesozoic and Cenozoic.…”

“…To test the possibility that these new snakes might fall outside of the snake clade in an overall analysis of squamate phylogeny, we included them in a recent large matrix of all squamates 25 . We also examined the more specific characters related to snakes, by including them in a data matrix originally developed to test snake ingroup relationships 3,7,8,[26][27][28] (Supplementary Methods; Supplementary Dataset 1). Both phylogenetic analyses were run using the software programs PAUP 29 and TNT 30 , the latter was also used to calculate bootstrap values of statistical support.…”

“…In our parsimony analyses of snake ingroup phylogeny, we submitted a taxon-character matrix of 27 terminal taxa and 237 characters, derived in large part from a recent study 3 that in turn had adapted characters and taxa from several other works 8,11,24,26,27,31 (Supplementary Methods; Supplementary Dataset 1). Our characterization of the Upper Cretaceous snake, Coniophis precedens 3 is more conservative than that given in a recent report, and is restricted to the vertebral assemblage, a single maxillary fragment (the other maxillary fragments are identified here as lizards, not snakes) and a fragmentary right dentary 3,24 .…”

Dinosaur incubation periods directly determined from growth-line counts in embryonic teeth show reptilian-grade development

“…Dinosaur eggs and attending parents (if present) (1, 33-36, 43) would have been exposed to prolonged risks (e.g., predation, starvation, and stochastic environmental events) (43,45,70,71). This exposure likely contributed to their tendency to lay large clutches with relatively smaller eggs as a means to counter high-mortality rates (43,72) within the egg (45, 46) and after hatching (73,74).…”