pterygostomialadj.n.
/ˌtɛrɪɡəˈstəʊmɪəl/, U.S. /ˌtɛrɪɡəˈstoʊmiəl/ Zoology.
Designating or relating to the anterior ventral region of the carapace in certain decapod crustaceans, flanking the buccal cavity (and sometimes extended into a pair of winglike projections at the anterior edge); (also) designating a spine that is sometimes present on the anterolateral angle of the carapace. Also as n.
ΚΠ
1877 T. H. Huxley Man. Anat. Invertebrated Animals vi. 341 The edges of the carapace pass completely in front of the bases of the limbs, and then turn suddenly forwards, parallel with one another and with the axis of the body, as the pterygostomial plates of Milne-Edwards.
1958 Jrnl. Paleontol. 32 501/2 Pterygostomial region inflated especially anteriorly.
1991 Jrnl. Crustacean Biol. 11 313/1 The carapace shape.., with its..strongly reflexed pterygostomials, and winglike lateral spines.., is clearly indicative of swimming mode of life.
1995 P. J. Hayward et al. in P. J. Hayward & J. S. Ryland Handbk. Marine Fauna N.W. Europe viii. 418/2 Hippolyte inermis [sc. a shrimp]... Carapace with one supraorbital spine, plus pterygostomial and hepatic spine.
This entry has been updated (OED Third Edition, September 2007; most recently modified version published online March 2022).
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adj.n.1877