Libys Münster 1842

Ferrante, Christophe, Menkveld-Gfeller, Ursula & Cavin, Lionel, 2022, The first Jurassic coelacanth from Switzerland, Swiss Journal of Palaeontology (15) 141 (1), pp. 1-20 : 4

Libys Münster 1842

Diagnosis (emended from Forey, 1998)

A genus of medium-sized, relatively deep-bodied coelacanths. Te head is nearly as deep as long. Te postparietal shield is much expanded posterolaterally where the supratemporals are particularly large. Te palate is deep and tapers rapidly anteriorly and the symplectic is also long, in keeping with the rather deep head. Te cheek is covered with large thin bones which are, however, well separated from one another. Te postorbital and lachrymojugal are broad and the preopercle is long and straplike. Te opercle is substantially deeper than broad. Te subopercle and the preorbital are absent. Sclerotic ossicles are present. In the lower jaw the angular shows a prominent dorsal expansion and the principal coronoid is developed posterodorsally as a rounded finger-like process. Te most obvious specialization of Libys are the sensory canals which open to the surface through a large groove crossed by pillars. Ornamentation is absent from the skull bones. Te shoulder girdle shows a very narrow cleithrum, clavicle and extracleithrum. Te anocleithrum is simple and sigmoid to blade-like. Te pelvic fin is located well behind the level of the anterior dorsal fin and is supported by very narrow pelvic bones. Te rays of the anterior dorsal fin and the caudal fin are ornamented with many prominent denticles. Fin rays of pectoral, ventral, posterior dorsal and anal fins are very closely articulated close to their bases. Te supplementary caudal fin is prominent developing apart from the caudal fin profile. Te lateral line scales carry a large sensory tube which opens through several secondary tubules. An ossified lung is present.