. Bulletin. Science; Natural history; Natural history. A NEW SPECIES OF PALEOCENE CHIMAEROID FROM CALIFORNIA Shelton p. Applegatei Abstract: A new species of Chimaeroid from the Paleocene of California is described which is the first New World record for the genus Ischyodus. The relationships of the present new species within the genus Ischyodus is discussed. The ratfishes of Chimaeroids are elasmobranch fishes known from the Devonian to the Recent. The suborder Chimaeroidei is known from the Jurassic. The oldest member being Ischyodus aalensis Reuss 1887. In these fishes the jaw ele- ments ar
. Bulletin. Science; Natural history; Natural history. A NEW SPECIES OF PALEOCENE CHIMAEROID FROM CALIFORNIA Shelton p. Applegatei Abstract: A new species of Chimaeroid from the Paleocene of California is described which is the first New World record for the genus Ischyodus. The relationships of the present new species within the genus Ischyodus is discussed. The ratfishes of Chimaeroids are elasmobranch fishes known from the Devonian to the Recent. The suborder Chimaeroidei is known from the Jurassic. The oldest member being Ischyodus aalensis Reuss 1887. In these fishes the jaw ele- ments are frequently preserved and are of taxo- nomic importance. The genus Ischyodus is extinct. Class : Holocephali Order: Chimaerif ormes Suborder: Chimaeroidei Family: Edaphodontiae Owen, 1845 Genus Ischyodus Egerton, 1843 Ischyodus zinsmeisteri, new species Holotype: LACM 37206, a lower right mandible, (Figs. 1, 2). Horizon and Locality: The locality where the specimen was collected is LACM Loc. number 3216, a dark rusty brown concretion in a limestone at lat. 34''14'58" N, and long. 118M2'52" W, T2N R18W, elevation 1200 to 1225 feet above sea level on a ridge between Meier and Runkle Canyons, Calabasas Quadrangle 1942, minute series scale 1:24,000 Simi Hills, Ventura Co, California. The collector was William Zinsmeister. The rocks are mapped as being marine and of Paleocene age (Jen- nings and Strand, 1969). Diaqiiosis: A mandible with an elongate and pointed beak. The symphyseal tritor is placed near the base of the jaw and is the smallest tritor. Description: The type (Fig, 2) is characterized by a long, straight beak which is inclined at an angle of approximately 45° from the vertical. Below and behind the beak are two well defined ridges which are directed anteriorly in the same manner as the beak. The ridges end in a raised cutting edge (Fig. 2B). The lateral side of the mandible (Fig. 2A) is flat except where the anterior one-half of the beak curves toward th
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