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单词 ptychodont
释义

ptychodontadj.n.

Brit. /ˈtʌɪkədɒnt/, /ˈtɪkəʊdɒnt/, U.S. /ˈtaɪkəˌdɑnt/, /ˈtɪkoʊˌdɑnt/
Origin: A borrowing from Greek, combined with an English element; partly modelled on a Latin lexical item. Etymons: Greek πτυχή , -odont comb. form.
Etymology: < ancient Greek πτυχή fold (see ptychode n.) + -odont comb. form. In later specific sense of the noun, after scientific Latin Ptychodontidae, family name (attributed to Jaekel, 1898; after Ptychodus, genus name ( L. Agassiz Poissons fossiles III. (1839) xiv. 56)).
Chiefly Palaeontology.
A. adj.
Of a tooth: having a series of ridges that acts as a grinding surface; (originally spec. of a mammalian molar) having the crown folded at the sides, with the folds often crossing the crown. Of a dentition: consisting of such teeth. Now rare.
ΚΠ
1874 Proc. Acad. Nat. Sci. Philadelphia 1873 371 Prof. Cope explained the scope of the paper read by him as follows:..the sides of the crown vertically plicate (Ptychodont).
1897 Amer. Naturalist 31 485 The dentition is lophodont, becoming ptychodont in some of the later forms.
1934 Jrnl. Mammalogy 15 183 A division distinguished by highly folded or ptychodont grinding teeth.
1966 Bull. Brit. Mus. Nat. Hist.: Geol. 11 vii.340 Forms with a ptychodont dentition..must have evolved from hybodontoids in which the dentition was homodont.
B. n.
An animal with ptychodont or similar teeth; spec. a fossil shark of the Cretaceous family Ptychodontidae, with teeth that have a series of parallel folds adapted for crushing shells.
ΚΠ
1895 I. K. Funk et al. Standard Dict. Eng. Lang. II. at Ptycho- Ptychodont, a. & n.
1954 Jrnl. Paleontol. 28 512/2 Elements of the fauna include..Toxochelid and Protostegid turtles, a Ptychodont and several sharks.
1977 Paleobiology 3 250/1 Kauffman..believes ptychodonts to have been important predators on inoceramid bivalves.
1993 Jrnl. Paleontol. 67 466/2 The ptychodonts and Cretoxyrhina mantelli are found as rare elements within the basal marine strata.
This entry has been updated (OED Third Edition, September 2007; most recently modified version published online March 2022).
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adj.n.1874
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