pygostyle

American  

[pahy-guh-stahyl] / ˈpaɪ gəˌstaɪl /

noun

Ornithology.

1. the bone at the posterior end of the spinal column in birds, formed by the fusion of several caudal vertebrae.

---

Other Word Forms

• pygostyled adjective
• pygostylous adjective

Etymology

Origin of pygostyle

1870–75; < Greek pȳgo- (combining form representing pȳgḗ rump) + stŷlos pillar

Example Sentences

The tail's anatomy enabled the scientists to rule out that it belonged to a bird because it was long and flexible and lacked a pygostyle, fused vertebrae that in birds support the tail feathers.

From Reuters • Dec. 8, 2016

"We can be sure of the source because the vertebrae are not fused into a rod or pygostyle as in modern birds and their closest relatives," he explained.

From BBC • Dec. 8, 2016

Caudal vertebrae more than thirteen, without a pygostyle, but with about twelve pairs of rectrices.

From Encyclopaedia Britannica, 11th Edition, Volume 3, Slice 7 "Bible" to "Bisectrix" by Various

Such a pygostyle is absent in Archaeopteryx, Hesperornis, Tinami and Ratitae, but it occurs individually in old specimens of the ostrich and the kiwi.

From Encyclopaedia Britannica, 11th Edition, Volume 3, Slice 7 "Bible" to "Bisectrix" by Various

About the size of a rook, its most obvious peculiarity is the long reptilian tail, composed of 20 vertebrae and not ending in a pygostyle.

From Encyclopaedia Britannica, 11th Edition, Volume 2, Slice 4 "Aram, Eugene" to "Arcueil" by Various