Here is some general info on bird feather tracts:
http://www.birds.cornell.edu/AllAboutBirds/studying/feathers/feathers
Feather Tracts:
Feathers are not attached to birds in a random manner over the entire body of the bird. Instead they are usually found in often linear tracts celled pterylae. The spaces on the bird's body without feather tracts are referred to as apteria. The densest area for feathers is often on the bird's head and neck.
Looking at skeletons and flight modes, pterosaurs resemble gulls and albatrosses. Similarly, some land dinosaurs resemble ostriches and chickens, and some aquatic dinosaurs resemble penguins.
ReplyDeleteYou are using the word "dinosaur" in an imprecise way.
ReplyDeleteCould you restate your point with more precision about which "dinosaur" taxa you are referring to please?
Ornithomimus and ostriches resemble each other, for example.
ReplyDeleteI had Dolichorhynchops and penguins in mind. Looking more closely at the skeletons, the resemblance now seems superficial, especially the lack of keel and the toes on the feet/rear-flippers.
ReplyDeleteOkay.
ReplyDeleteWhile not related specifically to this post, you may find this paper interesting in relation to your overall blog topic:
ReplyDeleteEarly Penguin Fossils, Plus Mitochondrial Genomes, Calibrate Avian Evolution (2006 Slack, et al)
http://mbe.oxfordjournals.org/content/23/6/1144.full.pdf?k=&ijkey=zaRIuJ8ctNRqLkV
"It is clear that modern birds from at least the latest Cretaceous lived at the same time as archaic birds including Hesperornis, Ichthyornis, and the diverse Enantiornithiformes. Pterosaurs, which also coexisted with early crown birds, show notable changes through the Late Cretaceous. There was a decrease in taxonomic diversity, and small- to medium-sized species disappeared well before the end of the Cretaceous. A simple reading of the fossil record might suggest competitive interactions with birds, but much more needs to be understood about pterosaur life histories."