Tharsis Giebel, 1848

Diagnosis

(Emended from Nybelin, 1974; based on a unique combination of characters; uniquely derived features among primitive teleosts are identified with an asterisk (∗).) Moderately large basal teleosts of about 27 cm in maximum length and fusiform body with a characteristic bend of the dorsal margin of the caudal fin giving the most posterior part of the body a peculiar shape and slightly asymmetric lobes of the fin (∗); parasphenoid without teeth; middle pit-line groove not extending on pterotic; cephalic sensory canals with numerous and simple sensory tubules; infraorbital 4 deeper than broad in contrast to infraorbital 3; postarticular process of the lower jaw poorly developed; posteroventral margin of preopercle without a notch; vertebrae with heavily ossified autocentra that strongly constrict the notochord; autocentra sculptured with pits, fossae and crests; caudal skeleton with eight or nine hypurals; last caudal vertebrae with a strong inclination of the neural (∗) and haemal (∗) spines toward body axis giving the vertebral column a characteristic aspect; with seven uroneurals distributed in an anterior series of four long uroneurals and other short three uroneurals positioned dorso-posteriorly; two elongate and well-developed tendon-bones “urodermals”; epaxial basal fulcra present; one elongate epaxial fringing fulcrum present.

Content: Tharsis dubius (Blainville, 1818) and T. elleri n. sp. See below Sect. 5 for the content of the genus.