Wednesday, November 14, 2018

Evolution: The First Four BIllion Years, Edited By Michael Rue & Joseph Travis, c. 2009.

576.8 EVO

Perhaps not as good as the Princeton textbook on evolution that is a few years newer, but this one seems more interesting to read.

I will skip ahead to "Dinosaurs: The model system for evolution" which begins on page 517.

Dinosaurs: pp 517 - 522 -- absolutely excellent essay
unique lineage of reptiles set apart from other groups by their erect posture and distinctive hip and hand structure
they are also the most successful terrestrial animals ever to inhabit the earth
their tenure spanned from 225 to 65 million years ago
if birds are in fact a lineage of carnivorous dinosaurs, their reign actually extends another 65 million years to the present day, where they dominate the aerial realm with over 9,000 species
physiologically they do not appear to have been like living reptiles; biologically they were perhaps more akin to today's birds and mammals, thus possibly explaining their great success


Archaeopteryx: pp 420 - 422

From wiki, fossil of complete Archaeopteryx, including indentations of feathers on wings and tail:

From Rue and Travis, page 420, Alan Feduccia:
  • the celebrated Berlin specimen has been called a veritable Rosetta stone of evolution because it is complete and beautifully preserved with outstretched wings
  • it illustrates and almost perfect intermediate between two major classes of vertebrates: birds and reptiles
  • feathers virtually identical to those of living birds, even down to their microstructure, as shown by electron microscopy
  • most paleontologists believe that Archaeopteryx was a capable although primitive powered flier, and the scapula and coracoid are primitive but join at a 90-degree angle, as in modern birds (note: there are modern birds today that could be considered to be "primitive powered fliers" and some don't fly at all)
  • the avian wings end with three reptilian fingers with sharp, highly recurved claws that closely mimic those of modern trunk-climbing mammals and woodpeckers, indicating that A. may have been a trunk climber
  • A. also had handleg wings as are present in the Chinese early Cretaceous microraptors
  • the skull of A. was both reptilian and avian, having reptilian teeth, but with an avian quadrate and cranial kinesis
  • the brain and inner ear were quite similar to modern birds, indicating a sophisticated flight ability
  • although A. remains the oldest known bird, more Mesozoic fossil birds have been discovered in the last two decades than from the 1860s to the 1970s; most came from teh Lower Cretaceous of China, and they represent various types of primitive birds, including the A.-like Jeholornis, which sports a long tail with 27 caudal vertebrae, and an anatomy much like that of the famous German Urvogel
Apparently Urvoget refers specifically to the German-specimen of the A. The Germans call A. by this name: Urvogel.

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