Opening today: Snakes on a ‘Pod
March 2, 2010
This is so unspeakably cool. Today in PLoS Biology (yay, free reprints for everybody!), Wilson et al. (2010) describe a new snake, Sanajeh indicus, based on multiple specimens from multiple sauropod nests where they were apparently eating baby sauropods! This is sweet for loads of reasons. There aren’t that many well-documented cases of predation in the fossil record in the first place. Predation on dinosaurs by non-dinosaurs is especially cool–you may remember the announcement of Repenomamus by Hu et al. (2005), a giant (for its time and clade) badger-sized mammal from China that was found with a gut full of baby Psittacosaurus. And as Wilson et al. note, this is only the second secure association of sauropod bones with eggs; the other is the Auca Mahuevo site in Patagonia that produced the first definitive sauropod eggs and embryos. If we learn half as much about sauropod biology from these Indian nests as we have from the Patagonian ones, it’s going to be an exciting decade.
Fossils of the new snake (left), sauropod egg (upper right), and sauropod hatchling (lower right), Wilson et al. 2010, fig 1.
The best bit, though, is the window this gives us into Mesozoic ecosystems. Dinosaurs made lots of offspring, and sauropods seem to have been particularly R-selected. With loads of multiton animals producing zillions of defenseless babies for most of the Mesozoic, it would be weird if other critters, dinosaurian and otherwise, didn’t take advantage of that seasonally abundant food source. It’s great to get some direct evidence.
This is like a swamp full of radioactive awesome. Go roll around in it and let it mutate you.
References
- Yaoming Hu, Jin Meng, Yuanqing Wang, Chuankui Li. 2005. Large Mesozoic mammals fed on young dinosaurs. Nature 433: 149–152.
- Wilson JA, Mohabey DM, Peters SE, Head JJ. 2010. Predation upon hatchling dinosaurs by a new snake from the Late Cretaceous of India. PLoS Biol 8(3): e1000322. doi:10.1371/journal.pbio.1000322
Addendum (from Mike)
Let’s not miss the opportunity to reproduce this classic, uh, life restoration, executed pre-emptively by William Stout decades before this fossil was even found! It’s from his 1981 book The Dinosaurs: a fantastic new view of a lost era.
Madtsoia crushes a young Laplatasaurus. By William Stout.
Sauropod Vertebra Picture of the Week 
March 2, 2010 at 11:29 pm
“With loads of multiton animals producing zillions of defenseless babies for most of the Mesozoic, it would be weird if other critters, dinosaurian and otherwise, didn’t take advantage of that seasonally abundant food source. It’s great to get some direct evidence.”
And we wonder why there’s such a wide variety of small theropods in the Morrison.
March 3, 2010 at 1:36 am
The real news is that at least two snakes were in the same fossil bed. They hunted in packs!
March 3, 2010 at 2:14 am
Whoa, I just heard about this on the radio minutes ago and it’s already here on SV-POW, complete with photoshopped, re-dated Hollywood poster! I gotta hand it to you Matt, I’ve seen fast before, but you’ve got super-human speed.
The very fact that snakes were found preserved in the act of eating baby sauropods is a one-in-a-million occurrence in itself.
I wonder how many “zillions” of defenseless babies there really were. Literally tons upon tons of the little critters. I think it’s just a matter of time before someone discovers a sauropod nesting ground big enough to make Horner’s “egg mountain” look like a speed-bump.
Is there any hint of what species the sauropod babies might be?
March 3, 2010 at 4:01 am
Props to Mike for tracking down that Stout restoration, I thought of it instantly when I read the press release but I couldn’t recall the source. I’m going to pull down that book off the shelf and revel in the glory of emaciated pterosaurs. Though, minor quibble, Stout really only anticipated the discovery by a few years, the specimen was originally collected in 1984!
March 3, 2010 at 11:53 am
HILARIOUS fake poster. Well done!
March 3, 2010 at 3:53 pm
I just want to say that that fake movie poster is hilarious.
March 3, 2010 at 8:12 pm
As both a dinosaur nut and an avid snake lover, I must say that this an absolutely AWESOME discovery! Seriously. Totally. Just… Wow.
March 5, 2010 at 7:08 pm
Bizarreness! I had not heard of the psittacosaurovore Repenomamus before, either.
Stout’s picture, wild and admirable, seems to me though to warp feasible perspective just a tad, where the snake crosses from outside left thigh to inside of left foreleg.
BTW anagrams: “Sauropod vertebra”
=”Superbrave or toad.”
=”Overabused parrot.”
March 6, 2010 at 10:35 pm
That is an incredibly cool discovery! A pretty big snake, too – 3.5 meters.
One thing, though: the paper says “The large body size (20–25 m) attained by the two titanosaur genera recognized from Indo-Pakistan, Isisaurus and Jainosaurus [39], may have been an effective deterrent to predators”
I’ve seen this said a lot, but it never seemed all that solid; the size gap between sauropods (barring Amphicoelias- or Puertasaurus-size mega-titans) and theropods isn’t any bigger than between wolves and moose, say. I’m not all that knowledgeable on this issue, though; does anyone know if there is any particular evidence that sauropods 10x more massive than the local predators were any more safe from predation than mammals 10x more massive than the local predators?
March 7, 2010 at 5:15 am
I certainly doubt that all the sauropods that show evidence of being gnawed on by allosaurs were just scavenged after dying of natural causes.
March 9, 2010 at 5:08 am
“A swamp full of radioactive awesome” – that’s just what I’ve been saying since hearing rumours of this specimen a few years back. Multiple snake-egg associations and a well-preserved skull are icing on the swamp.
But a big part of the awesome is that they’re NOT ‘macrostomatan’ snakes. Not only do madtsoiids fall outside ‘Macrostomata’ in analyses based on morphology, but when you do the DNA it turns out there’s no such clade anyway. _Sanajeh_ swallowed sauropods with jaws that a python or boa would just laugh at.
March 9, 2010 at 1:32 pm
Jamie Sterns wrote:
“With loads of multiton animals producing zillions of defenseless babies for most of the Mesozoic, it would be weird if other critters, dinosaurian and otherwise, didn’t take advantage of that seasonally abundant food source. It’s great to get some direct evidence.”
And we wonder why there’s such a wide variety of small theropods in the Morrison.
Especially since in the Gobi, fossils of “nests” of oviraptorids include the remains of smaller nonoviraptorosaurs, such as troodont skulls, mammals, etc. Prey, and potentially cannibalism, was not selective to a particular diet, so the hypothesis goes.
September 18, 2012 at 3:16 am
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