Caught In the Act... Fossilized Snake and Dino Eggs

Wow! Amazing Discovery. I can scarcely keep my enthusiasm under control. This is so very cool.

Thanks Mother Nature for preserving this one for us.

The skeleton of the 3.5 metre (11ft) snake, named Sanajeh indicus, was found inside a dinosaur nest in India, coiled around a crushed egg next to the body of a hatchling.

The hatchling would eventually have grown into a titanosaur, a huge plant-eating sauropod dinosaur measuring up to 25m and weighing about 100 tonnes.

The snake, whose name means “ancient gape [worm] from India”, would have been unable to eat dinosaur eggs themselves, as it lacked the wide jaws of modern species such as pythons. Once hatched, however, young dinosaurs would have been easier for it to eat.

And here is an important part:

The fossils were found in 1987 in the Lameta Formation in Gujarat, by a team led by Dhananjay Mohabey, of the Geological Survey of India — but the snake was originally misidentified as a hatchling dinosaur. (TimesOnline) above highlighting mine... see photo below for clarity.

The scientific abstract appears in the journal, Public Library of Science Biology, or PLoS Biology here.

Author Summary:

Snakes first appear in the fossil record towards the end of the dinosaur era, approximately 98 million years ago. Snake fossils from that time are fragmentary, usually consisting of parts of the backbone. Relatively complete snake fossils preserving skulls and occasionally hindlimbs are quite rare and have only been found in marine sediments in Afro-Arabia and Europe or in terrestrial sediments in South America. Early snake phylogeny remains controversial, in part because of the paucity of early fossils. We describe a new 3.5-m-long snake from the Late Cretaceous of western India that is preserved in an extraordinary setting—within a sauropod dinosaur nest, coiled around an egg and adjacent the remains of a ca. 0.5-m-long hatchling. Other snake-egg associations at the same site suggest that the new snake frequented nesting grounds and preyed on hatchling sauropods. We named this new snake Sanajeh indicus because of its provenance and its somewhat limited oral gape. Sanajeh broadens the geographical distribution of early snakes and helps resolve their phylogenetic affinities. We conclude that large body size and jaw mobility afforded some early snakes a greater diversity of prey items than previously suspected.

Introduction: (first two paragraphs)

Snakes are limbless reptiles that first appeared in the fossil record in the middle of the Cretaceous, approximately 98 million years ago [1]. Most species of living snakes are macrostomatans, which consume large prey items using a specialized gape achieved via a posteriorly displaced jaw joint, increased cranial kinesis, and an elongated skull and lower jaws. The evolution of large-gape feeding in macrostomatans has remained controversial owing to the scarcity of Cretaceous snake specimens preserving cranial and postcranial remains. Phylogenetic interpretation of these early snake fossils as either basal to all living snakes or to its subgroup Macrostomata has polarized views on snake origins, interrelationships, and ancestral habitat [2]–[6].

Here we describe an articulated snake fossil from uppermost Cretaceous horizons of Indo-Pakistan that is among the first such known from the subcontinent prior to the Miocene [7]. The new snake is preserved in an extraordinary setting—within a sauropod dinosaur nesting ground in association with eggs and a hatchling (Figures 1 and 2). The new fossils provide the first evidence, to our knowledge, of snake predation on hatchling dinosaurs and a rare example of non-dinosaurian predation on dinosaurs [8],[9]. Below we describe this new snake and its association with a sauropod egg clutch, resolve its phylogenetic relationships to other early snakes, and explore its implications for the evolution of wide-gape feeding in snakes and predation risks on sauropod dinosaurs.

(read more...)

PLoS ARTICLE currently available to everyone (click here)