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81-655: The dire wolf ( Aenocyon dirus / iː ˈ n ɒ s aɪ . ɒ n ˈ d aɪ r ə s / ) is an extinct canine . The dire wolf lived in the Americas (with a possible single record also known from East Asia ) during the Late Pleistocene and Early Holocene epochs (125,000–9,500 years ago). The species was named in 1858, four years after the first specimen had been found. Two subspecies are recognized: Aenocyon dirus guildayi and Aenocyon dirus dirus . The largest collection of its fossils has been obtained from
162-490: A maxilla found in Hermit's Cave, New Mexico as representing the nominate subspecies C. d. dirus . In 2021, a DNA study found the dire wolf to be a highly divergent lineage when compared with the extant wolf-like canines , and this finding is consistent with the previously proposed taxonomic classification of the dire wolf as genus Aenocyon (Ancient Greek: "terrible wolf") as proposed by Merriam in 1918. In North America,
243-665: A description of them. Nowak later referred to this material as C. armbrusteri ; then, in 2009, Tedford formally published a description of the specimens and noted that, although they exhibited some morphological characteristics of both C. armbrusteri and C. dirus , he referred to them only as C. dirus . A fossil discovered in the Horse Room of the Salamander Cave in the Black Hills of South Dakota may possibly be C. dirus ; if so, this fossil
324-455: A larger head when compared with a northern wolf of the same body size. The skull length could reach up to 310 mm (12 in) or longer, with a broader palate , frontal region , and zygomatic arches compared with the Yukon wolf. These dimensions make the skull very massive. Its sagittal crest was higher, with the inion showing a significant backward projection, and with the rear ends of
405-591: A lifelong career as a paleontological benefactress, financed his subsequent expeditions to Mount Shasta in 1902 and 1903, as well as his famous 1905 Saurian Expedition to the West Humboldt Range in Nevada . During this expedition Merriam unearthed 25 specimens of ichthyosaur , many of them considered the finest ever found. In 1903 he was recognized as an Associate Member of the Boone and Crockett Club ,
486-403: A skull and dentition adapted for hunting large and struggling prey; the shape of its skull and snout changed across time, and changes in the size of its body have been correlated with climate fluctuations. The last glacial period , commonly referred to as the "Ice Age", spanned 125,000–14,500 YBP and was the most recent glacial period within the current ice age , which occurred during
567-522: A study of skeletal remains showed differences in a few cranio-dental features and limb proportions between specimens from California and Mexico ( A. d. guildayi ) and those found from the east of the Continental Divide ( A. d. dirus ). A comparison of limb size shows that the rear limbs of A. d. guildayi were 8% shorter than the Yukon wolf due to a significantly shorter tibia and metatarsus , and that
648-610: A wildlife conservation organization founded in 1887 by Theodore Roosevelt and George Bird Grinnell . In 1912 he was appointed chairman of the Department of Paleontology at the University of California. That same year he began his famous studies of vertebrates at the La Brea Tar Pits. He and his students categorized many of the vertebrate fossils found at the site, and many more were placed in storage. The smilodon
729-487: A winter rainfall similar to that of modern coastal southern California, but the presence of coast redwood now found 600 kilometres (370 mi) to the north indicates a cooler, moister, and less seasonal climate than today. This environment supported large herbivores that were prey for dire wolves and their competitors. A range of animal and plant specimens that became entrapped and were then preserved in tar pits have been removed and studied so that researchers can learn about
810-540: Is comparable to the Yukon wolf in limb length. The largest A. d. dirus femur was found in Carroll Cave, Missouri, and measured 278 mm (10.9 in). A. d. guildayi is estimated to have weighed on average 60 kg (132 lb), and A. d. dirus weighed on average 68 kg (150 lb) with some specimens being larger, but these could not have exceeded 110 kg (243 lb) due to skeletal limits. In comparison,
891-460: Is not known. The lower premolars were relatively slightly larger than those of the gray wolf, and the dire wolf m1 was much larger and had more shearing ability. The dire wolf canines had greater bending strength than those of living canids of equivalent size and were similar to those of hyenas and felids. All these differences indicate that the dire wolf was able to deliver stronger bites than the gray wolf, and with its flexible and more rounded canines
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#1732801524789972-518: Is one of the earliest specimens on record. It was catalogued as Canis cf. C. dirus (where cf. in Latin means confer, uncertain). The fossil of a horse found in the Horse Room provided a uranium-series dating of 252,000 YBP and the Canis cf. dirus specimen was assumed to be from the same period. C. armbrusteri and C. dirus share some characteristics ( synapomorphies ) that imply
1053-505: Is the smallest canid to have existed. At the close of their genus 9 million years ago one Leptocyon lineage resembled the modern fox. The various species of Leptocyon branched 11.9 Mya into Vulpini (foxes) and Canini (canines). The canines spent two-thirds of their history in North America, before dispersing 7 million years ago into Asia, Europe, and Africa. One of the characteristics that distinguished them from
1134-517: Is thought to be due to temperature, prey, or habitat limitations imposed by proximity to the Laurentide and Cordilleran ice sheets that existed at the time. The dire wolf was about the same size as the largest modern gray wolves ( Canis lupus ): the Yukon wolf and the northwestern wolf . A. d. guildayi weighed on average 60 kilograms (132 lb) and A. d. dirus
1215-564: The African hunting dog (142), the gray wolf (136), the dhole (112), and the dingo (108). The bite force at the carnassials showed a similar trend to the canines. A predator's largest prey size is strongly influenced by its biomechanical limits. The morphology of the dire wolf was similar to that of its living relatives, and assuming that the dire wolf was a social hunter, then its high bite force relative to living canids suggests that it preyed on relatively large animals. The bite force rating of
1296-553: The American mastodon ( Mammut americanum ) were rare at La Brea. The horses remained mixed feeders and the pronghorns mixed browsers, but at the Last Glacial Maximum and its associated shift in vegetation the camels and bison were forced to rely more heavily on conifers. A study of isotope data of La Brea dire wolf fossils dated 10,000 YBP provides evidence that the horse was an important prey species at
1377-749: The Carnegie Institution in Washington, D.C. His departure caused the university to combine the Paleontology Department with the Geology Department, angering Merriam's benefactress, Annie Alexander, who subsequently founded and endowed the university's Museum of Paleontology . As the head of Carnegie Institution, Merriam's administrative duties led to a reduction in his research for the rest of his career. He accomplishments as president included helping to advance
1458-636: The Cerdocyonina , today represented by the South American canids, came into existence 6–5 million years ago. Its sister the wolf-like Canina came into existence 5 million years ago, however, they are likely to have originated as far back as 9 million years ago. Around 7 million years ago, the canines expanded into Eurasia and Africa, with Eucyon giving rise to the first of the genus Canis in Europe. Around 4–3 million years ago C. chihliensis ,
1539-606: The Last Glacial Period along with its Beringian prey. In 2010 Francisco Prevosti proposed that C. dirus was a sister taxon to C. lupus . C. dirus lived in the Late Pleistocene to the early Holocene , 125,000–10,000 YBP ( years before present ), in North and South America. The majority of fossils from the eastern C. d. dirus have been dated 125,000–75,000 YBP, but
1620-601: The Old World at the end of the Miocene , some 7 million to 8 million years ago. † Hesperocyoninae [REDACTED] † Borophaginae [REDACTED] Caninae [REDACTED] The genus Leptocyon (Greek: leptos slender + cyon dog) includes 11 species and was the first primitive canine. They were small and weighed around 2 kg. They first appeared in Sioux County, Nebraska in
1701-652: The Orellan era 34-32 million years ago, which was the beginning of the Oligocene . This was the same time as the appearance of the Borophaginae with whom they share features, indicating that these were two sister groups. Borophaginae skull and dentition were designed for a powerful killing bite compared with the Leptocyon which were designed for snatching small, fast-moving prey. The species L. delicatus
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#17328015247891782-467: The Quaternary extinction event along with its main prey species. Its reliance on megaherbivores has been proposed as the cause of its extinction, along with climatic change and competition with other species, or a combination of those factors. Dire wolves lived as recently as 9,500 years ago, according to dated remains. From the 1850s, the fossil remains of extinct large wolves were being found in
1863-579: The Younger Dryas cooling from 12,800 to 11,500 YBP, and the American megafaunal extinction event 12,700 YBP when 90 genera of mammals weighing over 44 kg (97 lb) became extinct. Isotope analysis can be used to identify some chemical elements, allowing researchers to make inferences about the diet of the species found in the pits. Isotope analysis of bone collagen extracted from La Brea specimens provides evidence that
1944-418: The baculum (penis bone) of the dire wolf is very different from that of all other living canids . Ecological factors such as habitat type, climate, prey specialization, and predatory competition have been shown to greatly influence gray wolf craniodental plasticity , which is an adaptation of the cranium and teeth due to the influences of the environment. Similarly, the dire wolf was a hypercarnivore, with
2025-509: The canid family came into existence 40 million years ago, and the canine subfamily Caninae about 32 million years ago. From the Caninae, the ancestors of the fox-like Vulpini and the dog-like Canini came into existence 9 million years ago. This group was first represented by Eucyon , and mostly by coyote -like Eucyon davisi that was spread widely across North America. From the Canini
2106-466: The dentition of genus Canis members , the dire wolf was considered the most evolutionary derived (advanced) wolf-like species in the Americas. The dire wolf could be identified separately from all other Canis species by its possession of: "P2 with a posterior cusplet; P3 with two posterior cusplets; M1 with a mestascylid, entocristed, entoconulid, and a transverse crest extending from the metaconid to
2187-435: The nasal bones extending relatively far back into the skull. A connected skeleton of a dire wolf from Rancho La Brea is difficult to find because the tar allows the bones to disassemble in many directions. Parts of a vertebral column have been assembled, and it was found to be similar to that of the modern wolf, with the same number of vertebrae. Geographic differences in dire wolves were not detected until 1984, when
2268-480: The Americas and that specimens found in Cumberland Cave, Maryland , appear to be C. armbrusteri diverging into C. dirus . Nowak believed that Canis edwardii was the first appearance of the wolf in North America, and it appears to be close to the lineage which produced C. armbrusteri and C. dirus . Tedford believes that the early wolf from China, Canis chihliensis , may have been
2349-642: The Borophaginae and Hesperocyoninae was their possession of less weight in their limbs and more length in their legs, which may have aided their dispersion. The first canine to arrive in Eurasia was the coyote-sized Canis cipio , whose scant fossils were found in Spain. However, the assignment of C. cipio within the canines to the genus Canis or genus Eucyon is not clear. The results of allozyme and chromosome analyses have previously suggested several phylogenetic divisions: DNA analysis shows that
2430-482: The La Brea pits dated in calendar years as follows: 82 specimens dated 13,000–14,000 YBP; 40 specimens dated 14,000–16,000 YBP; 77 specimens dated 14,000–18,000 YBP; 37 specimens dated 17,000–18,000 YBP; 26 specimens dated 21,000–30,000 YBP; 40 specimens dated 25,000–28,000 YBP; and 6 specimens dated 32,000–37,000 YBP. A specimen from Powder Mill Creek Cave, Missouri,
2511-602: The La Brea tar pits. Over 200,000 specimens (mostly fragments) have been recovered from the tar pits, with the remains ranging from Smilodon to squirrels, invertebrates, and plants. The time period represented in the pits includes the Last Glacial Maximum when global temperatures were 8 °C (14 °F) lower than today, the Pleistocene–Holocene transition ( Bølling-Allerød interval), the Oldest Dryas cooling,
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2592-470: The P4 had a relatively larger, more massive blade that enhanced slicing ability at the carnassial. The jaw of the dire wolf had a relatively broader and more massive temporalis muscle, able to generate slightly more bite force than the gray wolf. Due to the jaw arrangement, the dire wolf had less temporalis leverage than the gray wolf at the lower carnassial (m1) and lower p4, but the functional significance of this
2673-605: The Rancho La Brea Tar Pits in Los Angeles . Dire wolf remains have been found across a broad range of habitats including the plains, grasslands, and some forested mountain areas of North America, the arid savanna of South America. The sites range in elevation from sea level to 2,255 meters (7,400 ft). Dire wolf fossils have rarely been found north of 42°N latitude ; there have been only five unconfirmed reports above this latitude. This range restriction
2754-567: The United States, and it was not immediately clear that these all belonged to one species. The first specimen of what would later become associated with Aenocyon dirus was found in mid-1854 in the bed of the Ohio River near Evansville, Indiana . The fossilized jawbone with cheek teeth was obtained by the geologist Joseph Granville Norwood from an Evansville collector, Francis A. Linck. The paleontologist Joseph Leidy determined that
2835-413: The abundance of oak and chaparral decreased, but pines increased, creating open parklands similar to today's coastal montane /juniper woodlands. After 14,000 YBP, the abundance of conifers decreased, and those of the modern coastal plant communities, including oak woodland, chaparral, and coastal sage scrub , increased. The Santa Monica Plain lies north of the city of Santa Monica and extends along
2916-596: The ancestor of both C. armbrusteri and the gray wolf C. lupus . The sudden appearance of C. armbrusteri in mid-latitude North America during the Early Pleistocene 1.5 million years ago, along with the mammoth, suggests that it was an immigrant from Asia, with the gray wolf C. lupus evolving in Beringia later in the Pleistocene and entering mid-latitude North America during
2997-489: The average weight of the Yukon wolf is 43 kg (95 lb) for males and 37 kg (82 lb) for females. Individual weights for Yukon wolves can vary from 21 kg (46 lb) to 55 kg (121 lb), with one Yukon wolf weighing 79.4 kg (175 lb). These figures show the average dire wolf to be similar in size to the largest modern gray wolf. The remains of a complete male A. dirus are sometimes easy to identify compared to other Canis specimens because
3078-587: The battlefields. Eventually, when the two brothers were mustered out, they returned to Iowa, married, and raised families. As a young man, he began collecting Paleozoic invertebrate fossils near his Iowa home. He received a bachelor's degree from Lenox College in Hopkinton, Iowa , his father's alma mater , then went to the University of California to study geology and botany under Joseph Le Conte . He later went to Munich , Germany , to study under
3159-466: The bone material. In 2014 an attempt to extract DNA from a Columbian mammoth from the tar pits also failed, with the study concluding that organic compounds from the asphalt permeate the bones of all ancient samples from the La Brea pits, hindering the extraction of DNA samples. In 2021, researchers sequenced the nuclear DNA (from the cell nucleus) taken from five dire wolf fossils dating from 13,000 to 50,000 years ago. The sequences indicate
3240-399: The bone-consuming spotted hyena (117) challenged the common assumption that high bite force in the canines and the carnassials was necessary to consume bone. A study of the cranial measurements and jaw muscles of dire wolves found no significant differences with modern gray wolves in all but 4 of 15 measures. Upper dentition was the same except that the dire wolf had larger dimensions, and
3321-429: The dire wolf arose from an ancestral lineage that originated in the Americas and was separate to genus Canis . In 1992 an attempt was made to extract a mitochondrial DNA sequence from the skeletal remains of A. d. guildayi to compare its relationship to other Canis species. The attempt was unsuccessful because these remains had been removed from the La Brea pits and tar could not be removed from
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3402-520: The dire wolf lineage implies that other American fossil taxa, including C. armbrusteri and C. edwardii , may also belong to the dire wolf's lineage. The study's findings are consistent with the previously proposed taxonomic classification of the dire wolf as genus Aenocyon . The age of most dire wolf localities is determined solely by biostratigraphy , but biostratigraphy is an unreliable indicator within asphalt deposits. Some sites have been radiocarbon dated , with dire wolf specimens from
3483-424: The dire wolf lineage in the Americas, and that this geographic isolation allowed them to develop a degree of reproductive isolation since their divergence 5.7 million years ago. Coyotes, dholes, gray wolves, and the extinct Xenocyon evolved in Eurasia and expanded into North America relatively recently during the Late Pleistocene, therefore there was no admixture with the dire wolf. The long-term isolation of
3564-447: The dire wolf to be a highly divergent lineage which last shared a most recent common ancestor with the wolf-like canines 5.7 million years ago. The study also measured numerous dire wolf and gray wolf skeletal samples that showed their morphologies to be highly similar, which had led to the theory that the dire wolf and the gray wolf had a close evolutionary relationship. The morphological similarity between dire wolves and gray wolves
3645-417: The dire wolf, Smilodon , and the American lion ( Panthera atrox ) competed for the same prey. Their prey included the extinct camel Camelops hesternus , the extinct bison Bison antiquus , the "dwarf" pronghorn ( Capromeryx minor ), the equine Equus occidentalis , and Harlan's ground sloth ( Paramylodon harlani ) native to North American grasslands. The Columbian mammoth ( Mammuthus columbi ) and
3726-436: The dire wolf. In 1974 Robert A. Martin proposed that the large North American wolf C. armbrusteri (Armbruster's wolf) was C. lupus . Nowak, Kurtén, and Annalisa Berta proposed that C. dirus was not derived from C. lupus . In 1987, a new hypothesis proposed that a mammal population could give rise to a larger form called a hypermorph during times when food was abundant, but when food later became scarce
3807-849: The educational programs of the National Park Service , as well as helping to preserve the California redwoods . He was elected to the American Academy of Arts and Sciences in 1921. His published papers are collected in a four-volume set published in 1938 by the Carnegie Institution. Merriam was a founding member of the Galton Institute and a cautious political supporter of eugenics . Notably, his paternal first cousin Frank Merriam ,
3888-613: The effects of logging he witnessed in Redwood forests closer to San Francisco. A biography, which details his efforts to preserve wild lands in California and throughout the United States, was published in 2005. In 1919, Merriam served as president of the Geological Society of America . In 1920 he was appointed Dean of Faculty at the University of California, Berkeley, but he left that same year to become president of
3969-473: The famous paleontologist Karl von Zittel . In 1894 he returned to the U.S. and joined the faculty at the University of California, teaching and performing research in both vertebrate and invertebrate paleontology . In 1901 one of his lectures on paleontology inspired the young Annie Montague Alexander , who financed and took part in his expedition that year to Fossil Lake in Oregon . Alexander, who went on to
4050-415: The first three form monophyletic clades . The wolf-like canines and the South American canines together form the tribe Canini. Molecular data imply a North American origin of living Canidae some 10 Mya and an African origin of wolf-like canines ( Canis , Cuon , and Lycaon ), with the jackals being the most basal of this group. The South American clade is rooted by the maned wolf and bush dog, and
4131-455: The first wolf-sized member of Canis , arose in China and expanded to give rise to other wolf-like members across Eurasia and Africa. Members of the genus Canis would later expand into North America. The dire wolf evolved in North America. However, its ancestral lineage is debated, with two competing theories. The first theory is based on fossil morphology , which indicates that an expansion of
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#17328015247894212-567: The following year under the name C. dirus . The name C. primaevus (Leidy 1854) was later renamed Canis indianensis (Leidy 1869) when Leidy found out that the name C. primaevus had previously been used by the British naturalist Brian Houghton Hodgson for the dhole . In 1876 the zoologist Joel Asaph Allen discovered the remains of Canis mississippiensis (Allen 1876) and associated these with C. dirus (Leidy 1858) and Canis indianensis (Leidy 1869). As so little
4293-2394: The fox-like canines by the fennec fox and Blanford's fox. The gray fox and island fox are basal to the other clades; however, this topological difference is not strongly supported. The cladogram below is based on the phylogeny of Lindblad-Toh (2005) modified to incorporate recent findings on Canis , Vulpes , Lycalopex species, and Dusicyon . Canis latrans (coyote) [REDACTED] Canis rufus (red wolf) [REDACTED] Canis lycaon (algonquin wolf) [REDACTED] Canis lupus (gray wolf) [REDACTED] Canis familiaris (domestic dog) [REDACTED] Canis anthus (African wolf) [REDACTED] Canis simensis (Ethiopian wolf) [REDACTED] Canis aureus (golden jackal) [REDACTED] Cuon alpinus (dhole) [REDACTED] Lycaon pictus (African wild dog) [REDACTED] Lupulella adusta (side-striped jackal) [REDACTED] Lupulella mesomelas (black-backed jackal) [REDACTED] Speothos venaticus (bush dog) [REDACTED] Chrysocyon brachyurus (maned wolf) [REDACTED] † Dusicyon australis (Falkland Islands wolf) Lycalopex vetulus (hoary fox) [REDACTED] Lycalopex sechurae (Sechuran fox or Peruvian desert fox) Lycalopex fulvipes (Darwin's fox) Lycalopex gymnocercus (pampas fox) [REDACTED] Lycalopex griseus (South American gray fox or chilla) Lycalopex culpaeus (culpeo or Andean fox) [REDACTED] Cerdocyon thous (crab-eating fox) [REDACTED] Atelocynus microtis (short-eared dog) [REDACTED] Otocyon megalotis (bat-eared fox) [REDACTED] Nyctereutes (raccoon dogs) [REDACTED] Vulpes zerda (fennec fox) [REDACTED] Vulpes cana (Blanford's fox) [REDACTED] Vulpes chama (Cape fox) [REDACTED] Vulpes vulpes (red fox) [REDACTED] Vulpes rueppellii (Ruppell's fox) [REDACTED] Vulpes corsac (corsac fox) [REDACTED] Vulpes ferrilata (Tibetan sand fox) [REDACTED] Vulpes macrotis (kit fox) [REDACTED] Vulpes lagopus (Arctic fox) [REDACTED] Urocyon littoralis (island fox) [REDACTED] Urocyon cinereoargenteus (gray fox) [REDACTED] John Campbell Merriam John Campbell Merriam (October 20, 1869 – October 30, 1945)
4374-649: The front limbs were also shorter due to their slightly shorter lower bones. With its comparatively lighter and smaller limbs and massive head, A. d. guildayi was not as well adapted for running as timber wolves and coyotes. A. d. dirus possessed significantly longer limbs than A. d. guildayi . The forelimbs were 14% longer than A. d. guildayi due to 10% longer humeri , 15% longer radii , and 15% longer metacarpals . The rear limbs were 10% longer than A. d. guildayi due to 10% longer femora and tibiae, and 15% longer metatarsals . A. d. dirus
4455-449: The genus Canis out of Eurasia led to the dire wolf. The second theory is based on DNA evidence, which indicates that the dire wolf arose from an ancestral lineage that originated in the Americas and was separate from the genus Canis . [REDACTED] [REDACTED] [REDACTED] [REDACTED] [REDACTED] Morphological evidence based on fossil remains indicates an expansion of genus Canis from out of Eurasia led to
4536-465: The hyperconular shelf; M2 with entocristed and entoconulid." A study of the estimated bite force at the canine teeth of a large sample of living and fossil mammalian predators, when adjusted for the body mass, found that for placental mammals the bite force at the canines (in newtons /kilogram of body weight) was greatest in the dire wolf (163), followed among the modern canids by the four hypercarnivores that often prey on animals larger than themselves:
4617-468: The hypermorph would either adapt to a smaller form or go extinct. This hypothesis might explain the large body sizes found in many Late Pleistocene mammals compared to their modern counterparts. Both extinction and speciation – a process by which a new species splits from an older one – could occur together during periods of climatic extremes. Gloria D. Goulet agreed with Martin, proposing further that this hypothesis might explain
4698-491: The identity of these earliest fossils is not confirmed. In South America, C. dirus specimens dated to the Late Pleistocene were found along the north and west coasts, but none have been found in Argentina, an area that was inhabited by Canis gezi and Canis nehringi . Given their similarities and timeframes, it is proposed that C. gezi was the ancestor of Canis nehringi . One study found that C. dirus
4779-662: The last years of the Pleistocene era. The Ice Age reached its peak during the Last Glacial Maximum , when ice sheets began advancing from 33,000 YBP and reached their maximum limits 26,500 YBP. Deglaciation commenced in the Northern Hemisphere approximately 19,000 YBP and in Antarctica approximately 14,500 YBP, which is consistent with evidence that glacial meltwater
4860-440: The latter's descent from the former. The fossil record suggests C. dirus originated around 250,000 YBP in the open terrain of the mid-continent before expanding eastward and displacing its ancestor C. armbrusteri . The first appearance of C. dirus would therefore be 250,000 YBP in California and Nebraska, and later in the rest of the United States, Canada, Mexico, Venezuela, Ecuador, Bolivia, and Peru, but
4941-583: The paleontologist Ronald M. Nowak. In 1984 a study by Björn Kurtén recognized a geographic variation within the dire wolf populations and proposed two subspecies: Canis dirus guildayi (named by Kurtén in honor of the paleontologist John E. Guilday) for specimens from California and Mexico that exhibited shorter limbs and longer teeth, and Canis dirus dirus for specimens east of the North American Continental Divide that exhibited longer limbs and shorter teeth. Kurtén designated
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#17328015247895022-547: The past. The Rancho La Brea tar pits located near Los Angeles in Southern California are a collection of pits of sticky asphalt deposits that differ in deposition time from 40,000 to 12,000 YBP. Commencing 40,000 YBP, trapped asphalt has been moved through fissures to the surface by methane pressure, forming seeps that can cover several square meters and be 9–11 m (30–36 ft) deep. A large number of dire wolf fossils have been recovered from
5103-518: The previously found specimens under the name C. dirus (Leidy 1858). Because the rules of nomenclature stipulated that the name of a species should be the oldest name ever applied to it, Merriam therefore selected the name of Leidy's 1858 specimen, C. dirus . In 1915 the paleontologist Edward Troxell indicated his agreement with Merriam when he declared C. indianensis a synonym of C. dirus . In 1918, after studying these fossils, Merriam proposed consolidating their names under
5184-920: The same species, and that C. dirus had migrated from North America into South America, making it a participant in the Great American Interchange . In 2018, a study found that Canis gezi did not fall under genus Canis and should be classified under the subtribe Cerdocyonina , however no genus was proposed. The 2020 discovery of a claimed dire wolf fossil in northeast China indicates that dire wolves may have crossed Beringia when it existed. ( wolves , dogs , Eurasian jackals , etc.) [REDACTED] Cuon alpinus ( dhole ) [REDACTED] Lycaon pictus ( African wild dog ) [REDACTED] (African jackals ) [REDACTED] † Aenocyon dirus ( dire wolf ) [REDACTED] DNA evidence indicates
5265-477: The separate genus Aenocyon (from ainos , 'terrible' and cyon , 'dog') to become Aenocyon dirus , but at that time not everyone agreed with this extinct wolf being placed in a new genus separate from the genus Canis . Canis ayersi (Sellards 1916) and Aenocyon dirus (Merriam 1918) were recognized as synonyms of C. dirus by the paleontologist Ernest Lundelius in 1972. All of the above taxa were declared synonyms of C. dirus in 1979, according to
5346-484: The southern base of the Santa Monica Mountains , and 28,000–26,000 YBP it was dominated by coastal sage scrub, with cypress and pines at higher elevations. The Santa Monica Mountains supported a chaparral community on its slopes and isolated coast redwood and dogwood in its protected canyons, along with river communities that included willow, red cedar, and sycamore. These plant communities suggest
5427-598: The specimen represented an extinct species of wolf and reported it under the name of Canis primaevus . Norwood's letters to Leidy are preserved along with the type specimen (the first of a species that has a written description) at the Academy of Natural Sciences of Philadelphia . In 1857, while exploring the Niobrara River valley in Nebraska, Leidy found the vertebrae of an extinct Canis species that he reported
5508-455: The sudden appearance of C. dirus in North America and, judging from the similarities in their skull shapes, that C. lupus had given rise to the C. dirus hypermorph due to an abundance of game, a stable environment, and large competitors. The three paleontologists Xiaoming Wang , Richard H. Tedford , and Ronald M. Nowak propose that C. dirus evolved from Canis armbrusteri , with Nowak stating that both species arose in
5589-520: The time, and that sloth, mastodon, bison, and camel were less common in the dire wolf diet. This indicates that the dire wolf was not a prey specialist, and at the close of the Late Pleistocene before its extinction it was hunting or scavenging the most available herbivores. A study based on specimens found in Cedral, San Luis Potosi found that the dire wolf primarily preyed on herbivores that consumed C4 plants and on mixed-diet herbivores. When compared with
5670-524: The western C. d. guildayi fossils are not only smaller in size but more recent; thus it has been proposed that C. d. guildayi derived from C. d. dirus . However, there are disputed specimens of C. dirus that date to 250,000 YBP. Fossil specimens of C. dirus discovered at four sites in the Hay Springs area of Sheridan County, Nebraska , were named Aenocyon dirus nebrascensis (Frick 1930, undescribed), but Frick did not publish
5751-619: Was an American paleontologist , educator , and conservationist . The first vertebrate paleontologist on the West Coast of the United States, he is best known for his taxonomy of vertebrate fossils at the La Brea Tar Pits in Los Angeles , particularly with the genus Smilodon , more commonly known as the sabertooth cat. He is also known for his work to extend the reach of the National Park Service. He
5832-508: Was better adapted for struggling with its prey. North American (125,000–75,000 YBP) (50,000 YBP) Caninae Caninae (whose members are known as canines ( / k eɪ n aɪ n z / ) is the only living subfamily within Canidae , alongside the extinct Borophaginae and Hesperocyoninae . They first appeared in North America, during the Oligocene around 35 million years ago, subsequently spreading to Asia and elsewhere in
5913-540: Was born in Hopkinton, Iowa , the eldest child of postmaster, store proprietor, and American Civil War veteran Charles E. Merriam. His middle name Campbell was his mother's middle name, and the maiden name of his maternal grandmother. Both his father Charles E. Merriam and his paternal uncle Henry C. Merriam had served as officers in the 12th Iowa Infantry, Company K; after capture at the Battle of Shiloh , they were sent to Libby Prison for some time before being returned to
5994-440: Was concluded to be due to convergent evolution . Members of the wolf-like canines are known to hybridize with each other but the study could find no indication of genetic admixture from the five dire wolf samples with extant North American gray wolves and coyotes nor their common ancestor. This finding indicates that the wolf and coyote lineages evolved in isolation from the dire wolf lineage. The study proposes an early origin of
6075-555: Was cooler and with a more balanced supply of moisture than today. During the Last Glacial Maximum, the mean annual temperature decreased from 11 °C (52 °F) down to 5 °C (41 °F) degrees, and annual precipitation had decreased from 100 cm (39 in) down to 45 cm (18 in). This region was unaffected by the climatic effects of the Wisconsin glaciation and is thought to have been an Ice Age refugium for animals and cold-sensitive plants. By 24,000 YBP,
6156-559: Was dated at 13,170 YBP. The average dire wolf proportions were similar to those of two modern North American wolves: the Yukon wolf ( Canis lupus pambasileus ) and the Northwestern wolf ( Canis lupus occidentalis ). The largest northern wolves today have a shoulder height of up to 38 in (97 cm) and a body length of 69 in (180 cm). Some dire wolf specimens from Rancho La Brea are smaller than this, and some are larger. The dire wolf had smaller feet and
6237-493: Was found of these three specimens, Allen thought it best to leave each specimen listed under its provisional name until more material could be found to reveal their relationship. In 1908 the paleontologist John Campbell Merriam began retrieving numerous fossilized bone fragments of a large wolf from the Rancho La Brea tar pits. By 1912 he had found a skeleton sufficiently complete to be able to formally recognize these and
6318-713: Was later established as the California state fossil . In 1914, Merriam was elected to the American Philosophical Society . In 1918, he was elected to the United States National Academy of Sciences . That same year, he co-founded the Save the Redwoods League , which began significant preservation efforts after Merriam traveled the Redwood areas of Humboldt County, California in 1922 seeking to spare its old-growth
6399-518: Was more evolutionarily derived compared with C. nehringi , and was larger in the size and construction of its lower molars for more efficient predation. For this reason, some researchers have proposed that C. dirus may have originated in South America. Tedford proposed that C. armbrusteri was the common ancestor for both the North and South American wolves. Later studies concluded that C. dirus and C. nehringi were
6480-512: Was on average 68 kg (150 lb). Its skull and dentition matched those of C. lupus , but its teeth were larger with greater shearing ability, and its bite force at the canine tooth was stronger than any known Canis species. These characteristics are thought to be adaptations for preying on Late Pleistocene megaherbivores , and in North America, its prey is known to have included western horses , ground sloths , mastodons , ancient bison , and camels . Its extinction occurred during
6561-458: Was the primary source for an abrupt rise in sea level 14,500 YBP. Access into northern North America was blocked by the Wisconsin glaciation . The fossil evidence from the Americas points to the extinction mainly of large animals, termed Pleistocene megafauna , near the end of the last glaciation. Coastal southern California from 60,000 YBP to the end of the Last Glacial Maximum
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