. Bonner zoologische Monographien. Zoology. 85. : Pterotic of (A) Phoxinus erythrogaster (KXJ 5773, mm SL), and (B) P. cumberlanden- sis (KU 18934, mm SL) (a: ventral view; b: dorsal view). Scale bars = 1 mm. In the outgroups, the epioccipital is more or less rectangular; it bears a small sharp pro- cess at its posterior margin, and its anterior concavity on the ventral side bears no small deeper "subconcavity". Intercalar. The intercalar is a small paired endochondral bone placed at the postero- ventral side of the pterotic. It is triangular in shape and does not var
. Bonner zoologische Monographien. Zoology. 85. : Pterotic of (A) Phoxinus erythrogaster (KXJ 5773, mm SL), and (B) P. cumberlanden- sis (KU 18934, mm SL) (a: ventral view; b: dorsal view). Scale bars = 1 mm. In the outgroups, the epioccipital is more or less rectangular; it bears a small sharp pro- cess at its posterior margin, and its anterior concavity on the ventral side bears no small deeper "subconcavity". Intercalar. The intercalar is a small paired endochondral bone placed at the postero- ventral side of the pterotic. It is triangular in shape and does not vary significantly among Phoxinus species. Pterotic and lateral extrascapula (, B; 48A, B). Dorsally, in Phoxinus, the pterotic sutures the sphenotic anteriorly and epioccipital posteromedially. Ventrally the pterotic sutures the sphenotic anteriorly, the prootic mesially, and the exoccipital posteri- orly. The dorsal aspect of the pterotic is partially overlapped by the lateral extrascapular and the posttemporal in some species of the genus. The posterior portion of the pterotic forms the anterior part of the subtemporal fossa, and the lateral portion of the pterotic forms the dorsolateral portion of hyomandibular fossa. The pterotic is irregular-shaped in Phoxinus. The dorsal aspect (dermopterotic) of the pterotic is plate-like. The otic canal of the cephalic lateral line runs on the dorsal side of the bone. At the anterior part of the bone, an anteriorly directed process is present in most Phoxinus species (TS 75[1]), but the process is absent in P. tennesseensis, oreas, and erythrogaster (TS 75 [0]). A posteriorly directed process varying among the Phoxinus spe- cies exists on the posterolateral margin of the pterotic. The process is long and acute in P. cumberlandensis (TS 76[1]), but short and blunt in other species of Phoxinus and in the outgroups (TS 76 [0]). Ventrally, the pterotic bears two concavities, , the anterior and posterior concavities se- parated by
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Keywords: ., bookcentury1900, bookcollectionbiodiversity, booksubjectzoology
