Gli squali fossili
The bramble is a large (to 4 meters), wide-ranging deepwater shark of cold-temperate to tropical seas. Compagno (1984) notes that the distribution is spotty but the genus has been reported circumglobally, inhabiting continental and insular shelves and slopes from 11 to 900 meters. Usually found near the bottom, its known to feed on fish, crabs and cephalopods. Of the two extant species, one is circumglobal, Echinorhinus brucus BONNATERRE 1788 and the other, E. cookei PIETSCHMANN, 1928, limited to the Pacific. Only E. cookei bears the small (less than 5 mm in diameter) stellate denticles illustrated in many publications. E. brucus bears fewer and larger denticles which have a rounded base.
Fossil brambles are known only from isolated, but distinctive, teeth and denticles. The crown and root are severely compressed labio-lingually. The crown is made up of a distally directed cusp (mesial cutting edge may be weakly serrate), and depending on species, age and/or file position, mesial and distal cuplets.
Cappetta (1987) notes that the teeth may be up to 1.5 cm in width and have foramen on the labial (looks lingual to me) root face just below the crown. He notes that in species with mesial and distal cusplets, the mesial cusplets disappear in lateral files and in distal positions, the rear cusplets also disappear. Compagno noted that in extant bramble sharks, cusplets that are present on adult teeth are absent in juveniles.
Cappetta notes numerous fossil occurences and species beginning with Upper Cretaceous of Angola. Cenozoic brambles have been reported from Europe, Africa the Americas (North and South). Some of the species he lists include: E. blakei AGASSIZ, 1856 (Miocene of California), E. caspius GLICKMAN 1964 (Oligocene of former USSR & California), E. priscus ARAMBOURG 1952 (Lower Eocene, Morocco) and E. weltoni PFEIL 1983 - (Upper Eocene, Oregon). Kent (1994) includes E. priscus as present in the Eocene of Virginia, and E. blakei from the Miocene of Maryland, North Carolina and California.
Echinorhinus priscus ARAMBOURG 1952
Echinorhinus blakei AGASSIZ, 1856
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