Atlanticopristis
Atlanticopristis | |
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Hypothetical life reconstruction based on relatives | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Chondrichthyes |
Subclass: | Elasmobranchii |
Superorder: | Batoidea |
Order: | Rajiformes |
Family: | † Sclerorhynchidae
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Genus: | †Atlanticopristis Pereira & Medeiros, 2008 |
Species: | †A. equatorialis
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Binomial name | |
†Atlanticopristis equatorialis Pereira & Medeiros, 2008
|
Atlanticopristis (meaning "Atlantic saw") is an
Like all sawfish, it would have had a long snout armed with modified
Discovery and naming
Fossils of Atlanticopristis were discovered in the
The holotype tooth (CPHNAMA-VT 1174) was designated as such for being the most complete and well preserved specimen. Additionally, several specimens were assigned as paratypes: CPHNAMA-VT 1086, a single tooth and the largest specimen; CPHNAMA-VT 1085, two complete teeth; CPHNAMA-VT 1088 and CPHNAMA-VT 1173, two groups of four incomplete teeth each, all missing the tip of the crown; and CPHNAMA-VT 1173, two partial specimens with most of the crown.[1]
Portuguese
Description
The teeth on the rostrum (snout) of Atlanticopristis have a varied number of barbs at the front and rear margins. They are also laterally compressed, with both sides displaying thin enamel ridges extending outward from the base of the tooth, forming a fan shape. Some of the teeth also have grooves running down their length on both sides. The peduncle (or base) of the tooth is enlarged, and covered in irregular ridges, the bottom is typically concave, having a sub-rectangular or ellipsoid shape.[1]
The specimens range in size from 11.5 mm (0.45 inches) to 18.8 mm (0.74 inches). The holotype (CPHNAMA-VT 1174) is 15 mm (0.59 inches) in length, including the peduncle; which itself is 6.3 mm (0.24 inches) wide, and 3 mm (0.11 inches) long. It has a thickness of 3 mm (0.11 inches). The barb number on all specimens ranges from two to four barbs at the front margin and four to five at the rear, some specimens like CPHNAMA-VT 1085 having vestigial bumps that could be considered additional barbs.[1]
Sawfish evolved long snouts armed with rows of teeth on both sides, although these spines do not represent true teeth, but highly modified fish scales, or
Classification
Atlanticopristis belongs to the Sclerorhynchidae, a possibly
The formation of multiple barbs on both sides of the teeth is a characteristic also seen in the extinct Australian sawshark Ikamauius. In general, sclerorynchids all developed dentition closer to that of sawsharks than modern sawfish, but they are more closely related to the latter. This similarity is considered a case of convergent evolution, where unrelated organisms evolve analogous traits.[1]
Atlanticopristis and Onchopristis exhibit similarities to a Bolivian species of sclerorhynchid
Paleoecology
Atlanticopristis originates from the Alcântara Formation, which is dated to the
The paleoecological situation in Cenomanian Brazil highly resembles that of Middle Cretaceous north Africa, particularly the
References
- ^ .
- ^ ISBN 9788571931848.
- ^ ISSN 0895-9811.
- PMID 21437377.
- PMID 26473044.
- ISBN 978-3-89937-053-9.
- ISBN 9780643109148.
- ISSN 0895-9811.