Polymerichthys Temporal range: Middle Miocene | |
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Comparison of Longnosed lancetfish and P. nagurai | |
Scientific classification | |
Kingdom: | |
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Family: | Polymerichthyidae |
Genus: | Polymerichthys |
Species: | P. nagurai |
Binomial name | |
Polymerichthys nagurai Uyeno, 1967 [1] | |
Polymerichthys nagurai is an extinct, superficially eel-like alepisauroid from the Middle Miocene of Japan. The holotype specimen, no. 6599, was originally collected by Masayasu Nagura, a suzuri maker, around 1927. The specimen demonstrates several features typical of other families of Alepisauroidei, including head anatomy very similar to the daggertooths of Anotopteridae, and a well-developed dorsal fin similar to that of the lancetfish of Alepisauridae. [1]
The generic name literally translates as "many meristic fish," in reference to how the fish has numerous meristics units, including how the dorsal fin, which runs down the length of the body starting from behind the head, has somewhere between 300 and 350 rays, and how it has at least 186 vertebrae. The specific name honors the holotype's discoverer, Yuzo Nagura. [1]
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The Molidae comprise the family of the molas or ocean sunfishes, unusual fish whose bodies come to an end just behind the dorsal and anal fins, giving them a "half-fish" appearance. They are also the largest of the ray-finned bony fish, with the southern sunfish, Mola alexandrini, recorded at 4.6 m (15 ft) in length and 2,744 kg (6,049 lb) in weight.
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Alligator hailensis, or Haile alligator, is a large, extinct species of Alligator known from the early Pleistocene of Florida. It is named after the town of Haile, Florida, where it was found. Its age and skeletal morphology is intermediate between the geologically older Alligator mefferdi and the modern American alligator, making it a transitional fossil.
Acresuchus is an extinct monospecific genus of medium-sized caiman from the Late Miocene of western Brazil andVenezuela. The genus contains a single species, Acresuchus pachytemporalis. Acresuchus is a close relative of the giant caiman Purussaurus.
Caninemys is an extinct genus of large freshwater side-necked turtle, belonging to the family Podocnemididae. Its fossils have been found in Brazil and Colombia, in rocks dating back from the middle to late Miocene.
Dracopristis is a genus of extinct ctenacanthiform chondrichthyes that lived around 307 million years ago, during the Pennsylvanian sub-period of the Carboniferous period. The fish had 12 rows of short, squat teeth, and an array of spines on its dorsal fins. Because it has features similar to reptiles and the fictional kaiju, the fish is often nicknamed the "dragon shark" or "Godzilla shark". The main differentiation between ctenacanthiformes and true sharks is that ctenacanthiform mouths are larger but less flexible than the true sharks. The spines of the holotype fossil are about 0.57 meters long, and the whole body was around 2 meters (6 ft) long.
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