AURORA FOSSIL MUSEUM • Aurora, NC 27806-0352 • 252-322-4238 • aurorafossilmuseum.com • Aurfosmus@yahoo.com 17 Lemon Negaprion curybathrodon ½˝ - ¾˝ Rare • • CCP7 has a stratigraphic sequence which begins at the Pleistocene-Holocene transition. A fossil shark tooth was found in archaeological deposits dated to about 9000-9700 rcybp; it belongs to the genus Isurus (Elasmobranchii, Lamniformes, Isuridae). This species, unknown today in Santa Cruz marine coasts, lived in Patagonian seas during the fascinating problems is to figure out why in the world you find such a hodgepodge of different fossils of widely varying ages washing up on the beach. About the Lamniformes Cosmopolitodus hastalis Evolutionary Significance. It is widely regarded that Cosmopolitodus hastalis is the ancestor of the Great White Shark, Carcharodon carcharias. The triangular teeth of C. hastalis look almost exactly like those of C. carcharias but without the fine sharp serrations. In certain places in the world The evolutionary origin of the great white shark ( Carcharodon carcharias) is unclear, with debate centering around two principal hypotheses. The first, based on similarity in tooth shape, claims that C. carcharias originated from a group of extinct mako sharks that includes Isurus hastalis. Isurus hastalis, and a lot of small teeth. This was Bobby's first trip to Belgrade. What a nice way to start. I found a whole lot of nice hungry people who enjoyed the hot dogs, cold drinks and all the trimmings plus the excitement of the day. Hopefully we will have the same turn out at our fall trip. Happy Hunting to Everyone, not before laying hands on 2 huge (2+ inch) mako teeth Isurus hastalis and several smaller meg teeth Carcharias megalodon. The rest of us stuck it out for 6 hours or so and landed 3000-4000 lemon, bull, mako, snaggletooth and dusky shark teeth along with a couple whale earbones, fish vertebrae, gar teeth and scales, turtle shell Family Lamnidae: Isurus hastalis Isurus escheri Isurus sp. Carcharodon megalo­ don Family Cetorhinidae: Cetorhinus maxi­ mus Order Carcharhiniformes Family Scyliorhinidae: Scyliorhinus cf. coupatezi Family Carcharhinidae: Galeocerdo sp. Detached elasmobranch teeth and other remains including vertebral centra and scales are compa­ Vries 1985), the abundance of Carcharodon carcharias and the absence of Isurus hastalis from Bahía Inglesa suggest a Pliocene age. The El Rincón locality been dated on the basis of diatoms at between 13.9 and 12.1 MYBP (Tsuchi et al. 1988); I agree with the approximate age of this locality because of the presence of I. hastalis and absence of C. Fossil C. auriculatus Thresher 7-Gill Lemon Spinner Dusk Sharks C. meqalodon Nurse Mako of Florida C. an ustidens Carcharocles megalodon C. auriculatus to Isurus (I. hastalis) than it is to the species Carcharodon megalodon, and the latter is therefore best allocated to the genus Carcharocles. INTRODUCTION Isolated sharks' teeth are the most commonly preserved and collected vertebrate fossils from Neogene marine sediments worldwide. In contrast to the ubiquitous occurrence of sharks' Península de Baja California, Isurus hastalis (Agassiz), Carcharodon cf. C. arnoldi Jordan, Carcharodon sp., Carcharocles rectus (Agassiz), Carcharhinus (Prionace) antiquus (Agassiz), Hemipristis heteropleurus Agassiz y Aëtobatis smithii Jordan y Beal y en parte descubiertas en una revisión más cuidadosa de la literatura, respecto a to Isurus (I. hastalis) than it is to the species Carcharodon megalodon, and the latter is there