Archosaurs are a clade of reptiles (a group defined by a common ancestor) that includes the dinosaurs and by extension modern birds, as well as crocodiles. The flying pterosaurs are also Archosaurs, having evolved between crocodiles and dinosaurs. The marine reptiles Mosasaur and Plesiosaur, on ...
@nony - One of the most fascinating scientific stories which thrust the whole story of the Garden of Eden into the spotlight was in a breakthrough discovery of maternal descent through mitochondrial DNA. Scientists made a discovery that all of humans descended from one common female ancestor, be...
The age immediately prior to the dinosaurs was calledthe Permian. Although there were amphibious reptiles, early versions of the dinosaurs, the dominant life form was the trilobite, visually somewhere between a wood louse and an armadillo. In their heyday there were 15,000 kinds of trilobite. I...
Once upon a time, the word ‘dinosaur’ was applied to what were thought of as different lineages of distantly related land reptiles from the Mesozoic Era. These are the ‘lizard-hipped’ and ‘bird-hipped’ dinosaurs, named for the orientation of their pelvic bones. In biology, living thing...
Remarkable karyotypic similarities between some turtles and chicken suggest identity by descent, in other words that, aside from ~7 fissions, there were few interchromosomal changes from the archelosaur (bird-turtle) ancestor to the Avemetatarsalia (dinosaurs and pterosaurs), through the theropods ...
Answer to: Certain types of dinosaurs were bipedal (walked on two legs). What is a good reason that these creatures invariably had long tails if...
It was carnivorous, about 10 cm (4 inches) in length, and may be closely related to the ancestor of all extant mammals today. Credit: A.G. Martinelli, M.B. Soares, & C. Schwanke, PLoS ONE, 2016 But the reptilian sauropsids, previously having been overshadowed by the larger and ...
Dinosaurs are believed to have evolved in the Early Triassic period from carnivorous ornithosuchid ancestor. The oldest known ornithischian isPisanosaurus mertiiand its closely packed teeth suggest that they might have been herbivores. Diet of Theropoda ...
of thespecies that have been preserved in sediments that can be ac-cessed. And, as astonishingly strange as many of the dinosaursuncovered so far have been, there are equally odd species wait-ing to be unearthed. Reams of work based on as-yet-undevel-oped technologies and techniques will ...
Theory of Evolution Darwinand natural selection Natural selection, sometimes called “survival of the fittest,” was explained and made famous by Charles Darwin in his book, “On the Origin of Species”, published in 1859. In his book, Darwin suggested that individuals with the traits most appro...