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Arctosaurus osborni is known only from an incomplete cervical vertebra from the Upper Triassic Heiberg Formation of Cameron Island, Nunavut, Canada. Re-examination of the unique specimen indicates that it represents an archosauromorph reptile, possibly from the clade Allokotosauria. To date, Arctosaurus osborni represents the sole record of Late Triassic continental tetrapods from Nunavut and the northernmost record of such animals anywhere in the world. [ABSTRACT FROM AUTHOR]

Camelid remains are known from several Quaternary palaeontological localities in Alberta, yet most specimens are undescribed in the literature. Specimens reported here comprise a large sample of the known camelid record from the province and provide further insight into the record of Quaternary megafauna of western Canada. Remains from the Edmonton area include specimens pre- and post-dating the Last Glacial Maximum (LGM), whereas remains from the Vauxhall area are post-LGM. A metapodial fragment of a giant camel originally described as Titanotylopus from the Edmonton area is likely from earlier in the Pleistocene or late Pliocene. Camelid remains are not overly abundant in Alberta, but are widely distributed, having been recovered from several sites across the province. A new radiocarbon date of 11 280 ± 40 14C years BP on a radioulna of Camelops cf. C. hesternus represents only the fourth direct age assessment of a Quaternary camelid from Alberta. Radiocarbon data may suggest linkages to patterns of extirpation observed in camelid populations from northern Canada, followed by recolonization following deglaciation. [ABSTRACT FROM AUTHOR]

Foreyclupea loonensis, gen. et sp. nov., is described from the early-middle Albian Loon River Formation of the Northwest Territories, Canada. The only specimen of the new species was originally described as a part of an enigmatic taxon Erichalcis arcta in 1975, which was assigned to the Clupeomorpha. Since then, E. arcta has proven to be a composite taxon, made up of clupeomorph and non-clupeomorph specimens. The non-clupeomorph material was redescribed as a Euteleostei incertae sedis and retained the species name. Described herein is the fossil clupeomorph specimen originally assigned to Erichalcis arcta. As in other members of the superorder Clupeomorpha, the ventral margin of the body in the specimen is covered with spiny scutes, and the supratemporal commissural sensory canal passes through the parietals. Along with these diagnostic characters, the new taxon also shows primitive traits of the basal members of the group, including a medioparietal skull roof, unfused halves of the neural spines of the abdominal vertebrae, and no evidence of presence of the recessus lateralis. When included in a phylogenetic analysis of the Early Cretaceous clupeomorphs, the new species forms a clade with the Early Cretaceous clupeomorphs from Mexico and Brazil, Ranulfoichthys dorsonudum and Scutatuspinosus itapagipensis, respectively. [ABSTRACT FROM AUTHOR]

A recent survey of the middle Cenomanian Dunvegan Formation along the Peace River, Alberta, has yielded a partial skull of a large acipenseriform fish. The fossil was from an animal approximately 5 m in length, based on comparisons with living relatives. Though incomplete, this represents an important record of mid-Cretaceous fish from northern North America, as formations of this age are virtually unexplored in northern regions. This fossil is the oldest acipenserid from North America, and one of the most northerly known. [ABSTRACT FROM AUTHOR]

Myledaphus bipartitus is a Late Cretaceous (75 Ma) freshwater guitarfish, commonly represented by teeth and vertebral centra. The species was first described in 1876, but until now, very little has been known about its ecology and life history. We analyzed the age and growth using 117 fossilized centra (74 hemisectioned) from the Oldman and Dinosaur Park formations of southern Alberta. The resulting estimated maximum age was 16 years. Radial distance (RD) at the estimated asymptotic growth was calculated, and average RD at birth and 3 years were compared with two extant marine species of Rhinobatos ( R. productus and R. rhinobatos). Birth ring size ranged from 0.9 to 1.8 mm RD. At age three, centrum RD was between 2.8 and 4.6 mm RD for M. bipartitus and significantly less than R. productus and R. rhinobatos (5.0-6.6 mm RD). Myledaphus approached 'asymptotic' growth at 7.8 mm RD in the growth equation. The growth trajectory of Myledaphus had a similar slope to the Rhinobatos species, but with significantly smaller centrum RD. Rhinobatos rhinobatos also outlived Myledaphus by 8 years. [ABSTRACT FROM AUTHOR]