Ornithere: Difference between revisions
Jump to navigation
Jump to search
Content added Content deleted
m (clean up) |
|||
| Line 6: | Line 6: | ||
"Ornithere" (and the taxon name ''Ornitheria'') means bird-beast and stems from the bird-like appearance of the group. It is common for the names of sauceback taxa to end in ''-therium''. |
"Ornithere" (and the taxon name ''Ornitheria'') means bird-beast and stems from the bird-like appearance of the group. It is common for the names of sauceback taxa to end in ''-therium''. |
||
The name "jewel-eyed sauceback" stems from one of their unique |
The name "jewel-eyed sauceback" stems from one of their unique features—unlike most saucebacks which are blind, ornitheres have mirror-based eyes derived from their nostrils—called "eyestrils"—which have a shiny, jewel-like appearance. |
||
==Anatomy== |
==Anatomy== |
||
| Line 52: | Line 52: | ||
Ornitheres and their close relatives have limited up-down flexibility in their mandibles, unlike other saucebacks, as the muscles used to pivot the jaws up and down in other groups instead pull them together for a powerful bite. This gives strong-jawed species a superficially heart-shaped head, due to the powerful muscles bulging outwards. |
Ornitheres and their close relatives have limited up-down flexibility in their mandibles, unlike other saucebacks, as the muscles used to pivot the jaws up and down in other groups instead pull them together for a powerful bite. This gives strong-jawed species a superficially heart-shaped head, due to the powerful muscles bulging outwards. |
||
The oral |
The oral ring—a ring of chitinous teeth present in the mouths of all beastworms (and which was ancestral to all "arthropod-like" binucleids)--is comparatively far more basal in anatomy, though the teeth themselves commonly have serrations (which are absent in most other saucebacks). The teeth aid in both processing food and in pulling it down into the throat to be swallowed. Some species such as the quail raptor have reduced teeth. |
||
Ornitheres lack the lips that are present in other saucebacks, as their jaws, so much larger than the pincer-like jaws of more basal saucebacks, completely took over the role of closing the mouth; the lips only got in the way. This comes at a cost; some species cannot close their jaws fully because of secondary adaptations, so their mouths are exposed to open air and more prone to water loss. |
Ornitheres lack the lips that are present in other saucebacks, as their jaws, so much larger than the pincer-like jaws of more basal saucebacks, completely took over the role of closing the mouth; the lips only got in the way. This comes at a cost; some species cannot close their jaws fully because of secondary adaptations, so their mouths are exposed to open air and more prone to water loss. |
||
| Line 129: | Line 129: | ||
==References== |
==References== |
||
{{Reflist}} |
|||
[[Category:Common Names]] |
[[Category:Common Names]] |
||
[[Category:Group Overviews]] |
|||
[[category:Group_Overviews]] |
|||