rośliny-i-grzyby: Dire wolf

Evidence: 83 • authority: 94

Dire wolves are not commonly found north of California, and are especially rare in the late Pleistocene. According to the Paleobiology and Neotoma databases there are only five unconfirmed records of dire wolves above 42°N latitude: Fossil Lake, Oregon (late Pleistocene), American Falls Reservoir, Idaho (Sangamonian), Salamander Cave, South Dakota (Irvingtonian), and four closely grouped Irvingtonian sites in northern Nebraska. Several of these more northern sites where dire wolves are present are Irvingtonian, which is considered middle Pleistocene and was over by approximately 240,000 years ago. There are no confirmed records of Canis lupus in North America at that time. From these records it is unclear if dire wolves co‐existed at all with gray wolves during this time. The dearth of late Pleistocene dire wolves in more northerly latitudes begs the question of whether this species had range restrictions due to temperature, prey, habitat, etc. Since dire wolves are missing from these sites in the late Pleistocene, this region would have been prime territory for Beringian wolves expanding their range south along the glacier line. The late Pleistocene fauna in North America was different and more diverse than it is today. Mammals were found in greater species diversities, population numbers, and body sizes (Smith et al. 2003 ). The dire wolf ( Canis dirus ) was an iconic canid species that is often associated with the Ice Age, and unlike its close relative the gray wolf ( Canis lupus ) which came from Eurasia, the dire wolf arose in North America and is endemic to the Americas (Wang and Tedford 2008 ; Tedford et al. 2009 ). When dire wolves went extinct at the end of the Pleistocene epoch (circa 11,500 years ago), it enabled the gray wolf to move into the territory that is now mid‐continent North America in much larger numbers (Dundas 1999 ). Interestingly, the dire wolf is present, but not commonly found above 42°N latitude (Neotoma and PBDB). Gray wolves are well‐documented north of these latitudes, well into the Arctic Circle, in both the late Pleistocene and the Holocene ( www.neotomadb.org ). However, gray wolves are found in much lower densities in the late Pleistocene of North America. For example, at Rancho La Brea in southern California dire wolf fossils outnumber gray wolf fossils by a factor of more than five (A. Farrell, pers. comm. – Rancho la Brea collection internal database). Pleistocene diversity was much higher than today, for example there were three distinct wolf morphotypes (dire, gray, Beringian) in North America versus one today (gray). Previous fossil evidence suggested that these three groups overlapped ecologically, but split the landscape geographically. The Natural Trap Cave (NTC) fossil site in Wyoming, USA is an ideally placed late Pleistocene site to study the geographical movement of species from northern to middle North America before, during, and after the last glacial maximum. Until now, it has been unclear what type of wolf was present at NTC. We analyzed morphometrics of three wolf groups (dire, extant North American gray, Alaskan Beringian) to determine which wolves were present at NTC and what this indicates about wolf diversity and migration in Pleistocene North America. Results show NTC wolves group with Alaskan Beringian wolves. This provides the first morphological evidence for Beringian wolves in mid‐continental North America. Their location at NTC and their radiocarbon ages suggest that they followed a temporary channel through the glaciers. Results suggest high levels of competition and diversity in Pleistocene North American wolves. The presence of mid‐continental Beringian morphotypes adds important data for untangling the history of immigration and evolution of Canis in North America.

Evidence: 34 • authority: 88

Differential taphonomic effects of petroleum seeps and karstic sinkholes on ancient dire wolf teeth: Hydrocarbon impregnation preserves fossils for chemical and histological analysis. ABSTRACT Histological analysis of teeth can yield information on an organism’s growth and development, facilitating investigations of diet, health, environment, and long-term responses to selective pressures. In the Americas, an extraordinary abundance of Late Pleistocene fossils including teeth has been preserved in petroleum seeps, constituting a major source of information about biotic changes and adaptations at the end of the last glacial period. However, the usefulness of these fossils for histological st…

Evidence: 27 • authority: 80

Quaternary records of the dire wolf, Canis dirus, in North and South America

Evidence: 27 • authority: 72

The wolf (Canis lupus; pl.: wolves), also known as the grey wolf or gray wolf, is a canine native to Eurasia and North America. More than thirty subspecies of Canis lupus have been recognized, including the dog and dingo, though grey wolves, as popularly understood, include only naturally occurring wild subspecies. The wolf is the largest wild extant member of the family Canidae, and is further distinguished from other Canis species by its less pointed ears and muzzle, as well as a shorter torso and a longer tail. The wolf is nonetheless related closely enough to smaller Canis species, such as the coyote and the golden jackal, to produce fertile hybrids with them. The wolf's fur is usually…

Evidence: 20 • authority: 80

The legendary dire wolf may not have been a wolf at all

Evidence: 20 • authority: 72

The Great American Biotic Interchange (GABI), also known as the Great American Interchange and the Great American Faunal Interchange, was an important late Cenozoic paleozoogeographic biotic interchange event in which land and freshwater fauna migrated from North America to South America via Central America and vice versa, as the volcanic Isthmus of Panama rose up from the sea floor, forming a land bridge between the previously separated continents. Although earlier dispersals had occurred, probably over water, the migration accelerated dramatically about 2.7 million years (Ma) ago during the Piacenzian age. It resulted from the joining of the Neotropic (roughly South American) and Nearctic…

Evidence: 0 • authority: 71

Evidence: 0 • authority: 62

Evidence: — • authority: 65