June 19, 2012
Matt pointed out to me something that in retrospect is obvious, though I’d never thought about it before: the eyelashes of birds are not homologous with ours, since mammals’ eyelashes are modified hairs and birds don’t have hair. Instead, their lashes are modified feathers. It would be interesting to see both kinds of eyelash under a microscope and compare.
It certainly looks as though these “feathers” are simple unbranched filaments — much like the earliest protofeathers found on so many of those wacky Chinese raptors. I wonder how closely they resemble the ancestral state?
June 17, 2012
Check this baby out:
I know, I know what you’re thinking. “Enough with the vulgar overexposed skull of this beast, Taylor”, you cry: “Show us its zygapophyses!”
But of course.
This is from the anterior part of the tail, in right lateral view: the vertebrae that you see here are the third to seventh of those that carry chevrons.
The hot news here is of course that sperm whales go to all the bother of developing zygapophyses, right up at the top of their neural arches, down in a region of the body where they don’t come close to articulating and are of no conceivable use.
Anyone know why? Care to hazard a guess?
June 12, 2012
More from my flying visit to the Harvard Museum of Natural History. I found this exhibition of bird eggs very striking. In particular, it was shocking how much bigger the elephant-bird egg is than that of the ostrich.
From smallest to largest, the eggs are those of:
- Ruby-throated Hummingbird Archilochus colubris
- Common Redpoll Carduelis flammea
- House Finch Carpodacus mexicanus
- Eastern Screech Own Megascops asio
- Thick-billed Parrot Rhynchopsitta pachyrhyncho
- Red-necked Grebe Podiceps grisegeno
- Magnificent Frigatebird Fregata magnificens
- Red-tailed Hawk Buteo jamaicensis
- Cackling Goose Branta hutchinsii
- Bald Eagle Haliaeetus leucocephalus
- Tundra Swan Cygnus columbianus
- Wandering Albatross Diomedeo exulans
- Ostrich Struthio camelus
- Elephant bird Aepyornis sp.
As always, click through for full resolution.