The 366 daily episodes in 2014 were chronological snapshots of earth history, beginning with the Precambrian in January and on to the Cenozoic in December. You can find them all in the index in the right sidebar. In 2015, the daily episodes for each month were assembled into monthly packages, and a few new episodes were posted. Now, the blog/podcast is on an occasional schedule with diverse topics, and the Facebook Page showcases photos on Mineral Monday and Fossil Friday. Thanks for your interest!

Thursday, September 11, 2014

September 11. Rhynchocephalians





There were plenty of other reptile lineages evolving during the Triassic besides the archosaurs and their descendents, the dinosaurs. One group, the rhynchocephalians, became quite diverse soon after they emerged in middle Triassic time. They were reptiles covered with overlapping scales, in contrast to the other large group of reptiles, the archosaurs, which had more flexible skin and other coverings, including feathers in birds.  

Homoeosaurus, a rhynchocephalian. Photo by Haplochromis under GFDL 

The parent group to the rhynchocephalians also includes snakes and most lizards, but despite their abundance and diversity during the Triassic and later Mesozoic, only two species of rhynchocephalian survive today – two varieties of the tuatara of New Zealand, the only reptile native to New Zealand. It’s a large, 3-foot-long lizard-like reptile. As the only survivor of the rhynchocephalian order, its heritage goes back a long way and information about the tuatara may be significant to our understanding the evolution of snakes, dinosaurs, and birds.

The name rhynchocephalia means “beak-head” for various bony plates found on the skulls of the animal.
—Richard I. Gibson


Photo by Haplochromis under GFDL 

No comments:

Post a Comment