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12-539: Calcareous worm tube fossils are known from the formation. Planolites Indeterminate Acila A. (Truncacila) sp. Inoceramus I. cuvieri I. hobetsensis I. mamatensis I. teshioensis Nucula Indeterminate Teredolites Indeterminate The formation's thin shelled heteromorphic ammonites probably lived at depths of 36–183 m. The formation's ammonites generally suggest that its rock were of Turonian age. Eubostrychoceras E. japonicum Eubostrychoceras

24-759: Is a stub . You can help Misplaced Pages by expanding it . This Ediacaran biota -related article is a stub . You can help Misplaced Pages by expanding it . Ichnogenus An ichnotaxon (plural ichnotaxa ) is "a taxon based on the fossilized work of an organism", i.e. the non-human equivalent of an artifact . Ichnotaxon comes from the Ancient Greek ἴχνος ( íchnos ) meaning "track" and English taxon , itself derived from Ancient Greek τάξις ( táxis ) meaning "ordering". Ichnotaxa are names used to identify and distinguish morphologically distinctive ichnofossils , more commonly known as trace fossils ( fossil records of lifeforms ' movement, rather than of

36-852: Is an ichnogenus found throughout the Ediacaran and the Phanerozoic that is made during the feeding process of worm -like animals. The traces are generally small, 1–5 mm (0.039–0.197 in), unlined, and rarely branched, with fill that differs from the host rock. Planolites fossils have been found in Africa, Asia, Europe, Antarctica, and the Americas (with most specimens found in North America). Ichnospecies in Planolites include: This trace fossil -related article

48-623: Is known from Japan, Germany, and Madagascar. E. japonicum is Turonian, and likely confined to the middle Turonian. Gaudryceras G. denseplicatum Mesopusozia M. indopacifica Muramotoceras M. yezoense Muramotoceras is an unusual heteromorph previously known only from Japan. It is also middle Turonian. Otoscaphites O. teshioensis Synonym of Yezoites . Sciponoceras Indeterminate Tetragonites T. glabrus Yezoites Y. puerculus Platycanthus Indeterminate Small solitary hexacoral. An unidentified naticid snail

60-526: Is known from the formation. Biplica Indeterminate Opisthobranch A sponge spicule fragment is known from the formation. Dentalium Indeterminate Mako-like shark teeth are known from the formation. Other fish fossils include teeth, jaw fragments and scales. In 1994 , excavations for road material uncovered a hadrosaur specimen near the Glenn Highway , approximately 150 miles northeast of Anchorage . That Fall, excavation began on

72-500: The Talkeetna Mountains Hadrosaur was a hadrosaurid or lambeosaurid . Pasch and May also attempted to reconstruct how the Talkeetna Mountains Hadrosaur came to be preserved in the fossil record. They determined that the specimen formed from the remains of a hadrosaur carcass that had bloated with gasses and been washed out to sea. Since none of the skull bones were present, the head must have fallen off before

84-436: The carcass sank to the seafloor. The associated heteromorphic ammonites and inoceramid bivalves indicate that the Talkeetna Mountains Hadrosaur was buried at a depth greater than 35 m. The body came to rest on its left side with limbs outstretched. Pyrite was present in the rocks around the specimen, and may have formed from sulfur given off by the bacteria consuming the carcass. Planolites See text. Planolites

96-488: The hadrosaurs of North America and Asia. It was also the first associated skeleton of an individual dinosaur in Alaska. Their examination of the specimen found the "Talkeetna Mountains Hadrosaur" to be a juvenile animal about 3 m (10 feet) long. It preserves the bones of the forelimbs, part of the front feet, ribs, and tail vertebrae. Other remains probably include the back vertebrae and pelvis. The researchers could not tell if

108-504: The ichnogenus rank, based upon trace fossils that resemble each other in morphology but have subtle differences. Some authors have constructed detailed hierarchies up to ichnosuperclass, recognizing such fine detail as to identify ichnosuperorder and ichnoinfraclass, but such attempts are controversial. Due to the chaotic nature of trace fossil classification, several ichnogenera hold names normally affiliated with animal body fossils or plant fossils. For example, many ichnogenera are named with

120-478: The lifeforms themselves). They are assigned genus and species ranks by ichnologists , much like organisms in Linnaean taxonomy . These are known as ichnogenera and ichnospecies , respectively. "Ichnogenus" and "ichnospecies" are commonly abbreviated as "igen." and "isp.". The binomial names of ichnospecies and their genera are to be written in italics . Most researchers classify trace fossils only as far as

132-466: The specimen, now known as the "Talkeetna Mountains Hadrosaur" and concluded in the summer of 1996 . The rocks containing the specimen were part of the formation's Member Four. The specimen is now housed at the University of Alaska Museum . It was formally described for the scientific literature by Pasch and May in 2001 . The location of the specimen makes it significant as a biogeographic link between

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144-545: The suffix -phycus due to misidentification as algae. Edward Hitchcock was the first to use the now common -ichnus suffix in 1858, with Cochlichnus . Due to trace fossils' history of being difficult to classify, there have been several attempts to enforce consistency in the naming of ichnotaxa. The first edition of the International Code of Zoological Nomenclature , published in 1961, ruled that names of taxa published after 1930 should be 'accompanied by

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