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Showing results for tags 'pentlandia'.
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Grammatically incorrect form: Pentlandia macropterus. Taxonomy from Challands & Blaauwen, 2016. Emended diagnosis from Challands & Blaauwen, 2016, p. 3: "A medium-sized dipnoan (up to 40 cm) in which the I-bones do not meet medially posterior to the B-bone. The B-bone is 1.2 times as long as it is wide. The paired C-bones are 1.7 times long as they are wide. There are two paired Y-bones that lie lateral to the I-bone and contact the operculum along with bone 4, the J-bone, and the X-bone. Only one suboperculum is present. The X-bone carries the bifurcation for the supraorbital and infraorbital lateral line. There are six circumorbital bones, bone 3 being positioned dorsally and the largest. An A-bone is present posterior to the B-bone. The parasphenoid is short with a poorly developed posterior stalk. The entopterygoids are thin and L-shaped and carry subtriangular tooth plates with up to 12 rows of dentine-covered cusps. The lateral margins of the A-bone contact dorsal protuberances of the I-bone. The posterior dorsal fin is 17% of the total length of the animal with the anterior-most portion supported by a basal plate that carries three radials. Cosmine is not present on any scales or dermal bones. M-, O-, and P-bones are present in the snout region anterolateral to the E-bones but anterior to these bones the snout is unossified or poorly ossified and is not preserved in all but the largest specimens." Reconstruction from Challands & Blaauwen, 2016, p. 40: Identified by oilshale. References: Challands, T. and Blaauwen, Jan den (2016) A redescription of the Middle Devonian dipnoan Pentlandia macroptera Traquair, 1889, and an assessment of the Phaneropleuridae. Zoological Journal of the Linnean Society. p. 1-47. doi: 10.1111/zoj.12491 Volume 16: Fossil Fishes of Great Britain. Chapter 6: Mid-Devonian fossil fishes sites of Scotland. Site: JOHN O'GROATS, CAITHNESS (GCR ID: 353) Emma Jude, Zerina Johanson, Anton Kearsley and Matt Friedman(2014): Early evolution of the lungfish pectoral-fin endoskeleton: evidence from the Middle Devonian (Givetian) Pentlandia macroptera. Frontiers in Earth Science, 2014, Vol. 2, Article 18