August 31, 2012
Earlier this week, I got into a snit over the blinkered assertion that feathery dinosaurs are lame. I argued the opposite point–as I wrote at the time “Feathered dinosaurs are awesome. Deal with it.” How fortunate that a new paper this week offers proof of fuzzy dinosaur superiority. The evidence comes in the form of gut contents found within predatory dinosaurs that stalked Cretaceous China around 125 million years ago.
The carnivores in question are a pair of Sinocalliopteryx. These dinosaurs were close cousins of the much earlier Compsognathus, albeit quite a bit larger. While Compsognathus was turkey-size, about three feet long, Sinocalliopteryx grew to be about eight feet long. And this big predator was fluffy. The original description of the dinosaur mentioned the vestiges of simplified dinofuzz around the body of Sinocalliopteryx, and this makes sense given the dinosaur’s relationships. While considerably bigger than its close relatives, Sinocalliopteryx was a compsognathid–a group of theropod dinosaurs that also includes fuzzy forms such as Sinosauropteryx and Juravenator. Big or small, the compsognathids were hunters wrapped in wispy plumage.
And the initial description of Sinocalliopteryx mentioned something else. The skeleton that formed the basis of the original paper contained the leg of an unidentified dromaeosaurid dinosaur in its gut contents. Even though dromaeosaurids have long been cherished as sickle-clawed uber-predators, Sinocalliopteryx had clearly eaten the drumstick of one of the smaller feathered predators. Since then, paleontologists have identified a second Sinocalliopteryx with gut contents, and the two dinosaurs form the basis of a new PLoS One study by University of Alberta paleontologist Lida Xing and colleagues.
Looking back at the first Sinocalliopteryx, Xing and colleagues identified the victim as Sinosauropteryx. The second Sinocalliopteryx specimen had a different menu before it perished–its stomach contains the remains of two Confuciusornis, an archaic bird, and bones from an unidentified ornithischian dinosaur. But these gut contents invoke an aggravating mystery. Did these Sinocalliopteryx hunt their dinosaurian prey, or did they scavenge their meals?
This isn’t the first time paleontologists have puzzled over the meaning of predatory dinosaur gut contents. Earlier this year, Dave Hone and collaborators investigated a pterosaur bone found inside a Velociraptor, and last year Jingmai O’Connor and colleagues described a Microraptor with the remains of a bird in its gut (just to pick two examples of many). Frustratingly, though, it’s difficult to say how the dinosaurs obtained the meat. In the case of the Velociraptor, the researchers could not rule out hunting even though scavenging seemed the more likely option. Likewise, even though O’Connor and co-authors suggested their Microraptor hunted birds in the trees, the non-avian dinosaur could have just as easily scavenged a dead bird that fell to the forest floor. Gut contents tell us about what dinosaurs consumed, but they almost never provide direct evidence of how carnivores obtained flesh and bone to eat.
In the case of Sinocalliopteryx, the PLoS One study concludes that the dinosaur may have been skilled at catching live avian prey. The fact that one Sinocalliopteryx fed on two Confuciusornis in quick succession could mean that the large dinosaur was adept at nabbing early birds. “[T]he evidence of bird predation in Sinocalliopteryx,” Xing and colleagues conclude, “suggests that it was a highly capable stealth hunter.” Then again, the same researchers also note that their scenario “is speculative.” While it may seem improbable, the Sinocalliopteryx in question could have scavenged one or both of those birds, as well as the non-avian dinosaur remains in its stomach. We just don’t know. Like many predators, Sinocalliopteryx most likely hunted live prey and took advantage of carrion. Frustratingly, these fossil gut contents can’t tell us what happened in each case. Sinocalliopteryx may very well have been a skilled bird-slayer. Or perhaps not. The fact is that we don’t know for sure.
Perplexing feeding habits aside, there’s something else about the gut contents of Sinocalliopteryx that can give us a closer look at the dinosaur’s biology. In the dinosaur that ate the two birds and the ornithischian, the bone of the ornithischian dinosaur was corroded by stomach acid. The more delicate bird bones, by contrast, had not been so damaged. This means that the Sinocalliopteryx ate the ornithischian first, followed by one bird and, later, another. More than that, the acid damage indicates that at least some dinosaurs had highly-acidic foreguts where bone was broken down–comparable, but not exactly like, the stomachs of crocodilians and perhaps some bone-eating birds like the bearded vulture.
All of which is to say that Sinocalliopteryx is a great example of a fluffy dinosaur you wouldn’t want to mess with. Even if we can’t discern the backstory of each meaty morsel, the variety of prey in the Sinocalliopteryx stomachs shows that this dinosaur wasn’t a picky eater and may have even been a quick hunter that specializing in snapping up other feathery dinosaurs. For our fuzzy mammalian predecessors, hiding the Cretaceous forests, this would have been one scary dinosaur.
Xing L, Bell PR, Persons WS IV, Ji S, Miyashita T, et al. (2012) Abdominal Contents from Two Large Early Cretaceous Compsognathids (Dinosauria: Theropoda) Demonstrate Feeding on Confuciusornithids and Dromaeosaurids. PLoS ONE 7(8): e44012. doi:10.1371/journal.pone.0044012
June 22, 2011
Since I moved out West, I have been seeing dinosaurs everywhere. They are plastered on billboards, are the symbols of gas stations and—as I found out when I stopped by Salt Lake City’s Hatch Family Chocolates—sold as delicious chocolate morsels. When I stopped by the local confectionery they were selling these old-school sauropod and stegosaur tidbits. I don’t have to tell you they were good. NOM!
May 14, 2010
According to a short communication recently published in the Journal of Vertebrate Paleontology, an ancient marine reptile provided a feast for hungry sharks.
In 2006 paleontologists Tamaki Sato, Yoshikazu Hasegawa and Makoto Manabe described the remains of a previously-unknown kind of elasmosaurid, Futabasaurus suzukii, a long-necked predator that swam the seas in what is now Japan about 85 million years ago. Despite its role at the top of the food web, though, many of the bones of Futabasaurus bore toothmarks, and at least 82 shark teeth were found around the skeleton. There were even several shark teeth embedded in the skeleton. Not only had the scientists found a new marine reptile, but they had stumbled upon a prehistoric shark buffet.
According to the new analysis, the shark teeth belong to the species Cretalamna appendiculata, a shark that belonged to the group that contains modern great white, mako and sand tiger sharks. The question is whether the sharks attacked the plesiosaur or were scavenging its carcass. Even though it had previously been proposed that the elasmosaur remains recorded an attack by multiple sharks, the authors of a new study converge on a different scenario.
While the elasmosaur’s cause of death is unknown, it appears that it sank to the bottom and was left uncovered for a short period of time, no more than a few months. (The fact that much of the skeleton remained articulated argues against the “bloat and float” scenario in which a decomposing carcass wells with gas, floats to the surface, and begins to drop body parts over a wide area as it rots or is scavenged.) During this time multiple sharks (at least six) fed upon it, and while the carcass may have been the site of a shark “feeding frenzy,” it is impossible to tell when each individual shark came and fed. Despite these uncertainties, however, this specimen of Futabasaurus is remarkable because it contains the fleeting records of life, death and scavenging during a time tens of millions of years before our own.
Shimada, K., Tsuihiji, T., Sato, T., & Hasegawa, Y. (2010). A Remarkable Case of a Shark-Bitten Elasmosaurid Plesiosaur Journal of Vertebrate Paleontology, 30 (2), 592-597 DOI: 10.1080/02724631003621920
January 4, 2010
Every once in a while I like to order out from my favorite local Chinese restaurant, and I can’t help but always get my favorite dinosaur dish: sesame chicken. Admittedly I often eat it with the help of a fork, but I might have to switch to a different kind of utensil. The company 4physics is now selling dinosaur chopsticks, plastic prehistoric critters with extra-long legs that can be squeezed together to pick up food. The eight-piece set comes with an Ankylosaurus, “Brontosaurus,” Parasaurolophus, Pteranodon (not a dinosaur), Stegosaurus, Tyrannosaurus, Triceratops, and Velociraptor, although I have my doubts about the claim that using the chopsticks “makes finger foods more tasty.” I know dinosaurs are awesome, but they’re not that awesome.
[Hat-tip to Gizmodo.]
June 18, 2009
Parents of young dino fans know it has to happen eventually. When birthday time rolls around, their future paleontologist wants a cake in the shape of, or at least adorned with, dinosaurs. There’s plenty of ways to do this. For those short on time there’s always the option of running to the supermarket and placing a few plastic dinosaurs on top, but what if you want to make something a little more elaborate? Lucky for you, the website Howdini.com has a step-by-step video showing you how to make a pretty neat-looking dinosaur cake:
I’m no wiz in the kitchen (I almost have all the scorch marks cleaned up after my last attempt at cooking), but this doesn’t look too difficult. Maybe I’ll make it for an end-of-summer dinosaur party, but knowing my luck with baking, I might want to try a practice run first.