A new species of Cretaceous bird, identified from a fossil found in Liaoning Province, China, suggests some early birds evolved teeth adapted for specialized diets.
According to a study published in the Journal of Vertebrate Paleontology, the enantiornithine bird named Sulcavis geeorum had a durophagous diet – its teeth were capable of eating prey with hard exoskeletons like insects or crabs.
Enantiornithine birds are an early group of birds, and the most numerous birds from the Mesozoic – the time of the dinosaurs.
Sulcavis lived during the Early Cretaceous about 121-125 million years ago in what is now China. Paleontologists believe the teeth of the new specimen greatly increase the known diversity of tooth shape in early birds, and hints at previously unrecognized ecological diversity.
Sulcavis is the first discovery of a bird with ornamented tooth enamel.
The dinosaurs – from which birds evolved – are mostly characterized by carnivorous teeth with special features for eating meat. The enantiornithines are unique among birds in showing minimal tooth reduction and a diversity of dental patterns. Sulcavis had robust teeth with grooves on the inside surface, which likely strengthened the teeth against harder food items.
No previous bird species have preserved ridges, striations, serrated edges, or any other form of dental ornamentation.
“While other birds were losing their teeth, enantiornithines were evolving new morphologies and dental specializations. We still don’t understand why enantiornithines were so successful in the Cretaceous but then died out – maybe differences in diet played a part,” explained lead author Dr Jingmai O’Connor of the Natural History Museum of Los Angeles County’s Dinosaur Institute.
“This study highlights again how uneven the diversity of birds was during the Cretaceous. There are many more enantiornithines than any other group of early birds, each one with its own anatomical specialization,” added co-author Dr Luis Chiappe, also from the Dinosaur Institute.
Bibliographic information: O’Connor, J.K., Y. Zhang, L. M. Chiappe, Q. Meng, L. Quanguo, and L. Di. 2013. A new enantiornithine from the Yixian formation with the first recognized avian enamel specialization. Journal of Vertebrate Paleontology 33(1):1-12