Pinacosuchus is an extinct genus of crocodylomorph. Its fossils were found in the Late Cretaceous-age North Horn Formation of Utah (United States). Pinacosuchus was a diminutive crocodylomorph with spiky armor, and is known only from meagre remains.
Charles W. Gilmore named Pinacosuchus in 1942 for USNM 16592, consisting of a fragment of upper jaw, seven partial vertebrae, a partial coracoid, a partial thigh bone, numerous pieces of bony armor, and other fragments. This specimen was discovered at the "Lizard Locality" in the Manti National Forest, Emery County, Utah. The type species is P. mantiensis. Gilmore had difficulty classifying the specimen, due to its fragmentary nature. He ruled out all then-known orders of reptiles on anatomical ground except for Crocodilia (which had a more expansive definition at the time) and the nebulous thecodontia. He considered a pseudosuchian thecodont identity, but eliminated it because all members were of Triassic age or older. Pinacosuchus would have been an archaic crocodilian because it lacked the procoelous vertebrae (concave articulation surface on the anterior face of the bone, and convex articulation on the posterior face) of more derived crocodilians, instead having amphicoelous vertebrae (concave articulations on both faces).[1]
Pinacosuchus would have been a very small crocodylomorph. The sacrum (the vertebra supporting the hips) of USNM 16592 was only 14.3 millimetres (0.56 in) long. Gilmore regarded the specimen as an adult because the vertebrae lacked sutures for their neural arches, a sign of maturity.[1] This assessment was supported by O'Neill and colleagues, comparing Pinacosuchus to their new spiked crocodilian Akanthosuchus.[2] The armor of Pinacosuchus was found disarticulated. Gilmore divided the armor into five categories: simple rectangular scutes; ridged rooflike scutes; thickened rectangular scutes with asymmetrically-positioned sharp spines overhanging the borders; small pointed spines with thickened bases; and more elongate pointed spines with thickened bases.[1] The genus is briefly mentioned in Cifelli et al. (1999) under the misspelling "Pinasuchus". In the text of this publication, it is mentioned that Kenneth Carpenter had observed "some faint resemblances" to the Morrison Formation goniopholidid genus Eutretauranosuchus. It is incorrectly listed as a possible ankylosaur in Table 1.[3]
Pinacosuchus is an extinct genus of crocodylomorph. Its fossils were found in the Late Cretaceous-age North Horn Formation of Utah (United States). Pinacosuchus was a diminutive crocodylomorph with spiky armor, and is known only from meagre remains.
畢那可鱷屬（學名：Pinacosuchus）是已滅絕鱷形超目的一屬，化石被發現於美國猶他州的北角組（North Horn Formation）地層，地質年代相當於白堊紀晚期。畢那可鱷的化石不多，但具有角狀尖刺，這特徵在鱷形超目裡相當獨特。
正模標本（編號USNM 16592）被發現於美國猶他州艾麥里縣的曼泰國家森林，包含：上頜的碎片、七節部分脊椎、一個部分鳥喙骨、一個部分股骨、多塊鱗甲（皮內成骨）、以及其他骨頭碎片。在1942年，古生物學家查爾斯·惠特尼·吉爾摩將這些化石進行敘述、命名，模式種是曼泰畢那可鱷（P. mantiensis）。由於化石過於破碎，吉爾摩很難做出準確的分類。吉爾摩排除爬行動物的大部分目，認為畢那可鱷可能屬於鱷目（那個年代的鱷目範圍較大）、以及槽齒目。吉爾摩覺得這個動物很類似偽鱷亞目，但偽鱷類生存於三疊紀或更早時期，因此也排除這個可能。吉爾摩認為畢那可鱷可能是古代鱷魚，因為其脊椎是雙凹型脊椎，不是前凹型脊椎，這是現代鱷魚的特徵；前凹型脊椎是椎體前側有凹處，後側有凸處，前後彼此相連接[1]。
畢那可鱷是種非常小型的鱷形類動物。薦骨的長度為14.3公分。由於脊椎神經弓缺乏骨縫，顯示這個化石是個成年個體[1]。數十年後，其他研究人員命名另一種多尖刺鱷形類（Akanthosuchus）時，也支持畢那可鱷是成年個體的看法[2]。畢那可鱷的化石被發現時，鱗甲呈脫落狀態。吉爾摩將鱗甲分為五種形態：矩形鱗甲、有稜脊的隆起鱗甲、帶有銳利尖刺的厚矩形鱗甲、基部厚的小型尖刺、基部厚的延長尖刺[1]。
