Trigonid


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Related to Trigonid: lophodont

Tri´go`nid


4.(Zool.) The cutting region of the crown of an upper molar, usually the anterior part. That of a lower molar is the Tri"go*nid ( ).
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The trigonid and talonid are connected to the prehypocristid and preentocristid by the postprotocristid and the postmetacristid with prehypocristid and preentocristid, respectively.
The paraconid was probably absent, although the state of preservation of the tooth does not permit a firm conclusion to be reached, although close inspection reveals that the trigonid valley was very small, tall and closed anteriorly.
m1 Antero-posterior Trigonid Talonid length width width PCS Sorex 1.27 0.75 0.80 S.
Ankylodon is characterized by having moderate curvature of the trigonid, reduced paraconid, strongly convex buccal margin of the protoconid and metaconid, and boarder nature of the tooth when compared to Metacodon (1) all of which are seen in PTRM 1600.
The trigonid is formed by subequal protoconid and metaconid with the protoconid slightly mesiad of the metaconid.
The trigonid and talonid are not equal in size; the trigonid is narrower than the talonid.
Abbreviations.- AL2-C, Alcoy-2C; AL2-D, Alcoy-2D; CLC, Calicasas; L, Length; LB2B, La Bullana 2B; LB3, La Bullana 3; MN, European Neogene land mammal Units; MNA, Mina; PUR, Purcal; SCSIE (UV), Servei Central de Suport a la Investigacio Experimental de la Universitat de Valencia; THC, Tollo de Chiclana; TLW, talonid width; TRW, trigonid width; W, Width.
SDSM 82104 exhibits tall, conical cusps on the trigonid and a nearly identical size and morphology to the paratype specimen.
Siamotragulus and Yunnanotherium differ from those of the studied samples in: more selenodont and hypsodont aspect premetacristid is well developed and closes the anterior side of the trigonid and a strong ectostylid (Thomas et al.
The lower carnassial suffers a marked reduction of the trigonid with regard to the talonid, which becomes much longer.