| 释义 |
synapsid, a. and n.|sɪˈnæpsɪd|
[a. mod.L. Synapsida (H. F. Osborn 1903, in Mem. Amer. Mus. Nat. Hist. I. 455), f. syn- + Gr. ἁψίς, ἁψιδ- arch: see -id3.]
A. adj. Of or pertaining to the subclass Synapsida, which includes fossil reptiles having a single temporal opening on each side of the skull. So syˈnapsidan a.
B. n. A fossil reptile of the subclass Synapsida, showing a skull structure with some mammalian characteristics.
1903Mem. Amer. Mus. Nat. Hist. I. 460 In all Synapsidan types above the Cotylosauria the squamosals and pro-squamosals early coalesce. 1910Bull. Amer. Mus. Nat. Hist. XXVII. 114 The Synapsid reptiles..may conveniently be approached by a cursory review of the reptilian orders. 1933A. S. Romer Vertebr. Paleontol. vi. 128 Forms with one opening (in which it was presumed that the two openings had fused into one), [were termed] ‘synapsid’ (fused-arched) reptiles. 1956― Osteol. Reptiles ii. 473 The mesosaurs..are associated with the synapsid orders. Ibid. 474 The synapsids..seem to be a very natural assemblage. 1974D. & M. Webster Compar. Vertebr. Morphol. v. 102 The presence of this bone in both monotremes, where it is apparently functionless, as well as in metatherians is particularly confusing since there is no indication of a marsupial bone in synapsid reptiles. 1980Nature 24 Jan. 378/2 The mammals arose from advanced synapsids in the Upper Triassic. Ibid., An alternative view of the origin of the synapsid skull is that the ancestral condition of the temporal region consisted of a large supratemporal bone which was in contact anteriorly with the postorbital. |