Tag: beardog

  • Cynodictis: A “Slender Dog Marten” from 28 Million Years Ago

    Cynodictis: A “Slender Dog Marten” from 28 Million Years Ago

    1. Cynodictis was an extinct carnivorous mammal belonging to the amphicyonid family.
    2. It lived between 37.9 and 28.4 million years ago, during the Late Eocene and Early Oligocene periods.
    3. Cynodictis had a slender, marten-like body, specialized dentition, and was not the progenitor of modern canids.

    The extinct carnivorous mammal genus Cynodictis belonged to the amphicyonid family. Its fossils have been found in several parts of Europe and Asia, and Cynodictis is thought to have existed between 37.9 and 28.4 million years ago, during the Late Eocene and Early Oligocene periods.

    Cynodictis was first described by Bravard and Pomel in 1850.

    How Did Cynodictis Look Like?

    Cynodictis teeth.
    Cynodictis teeth.

    The closest comparison of Cynodictis would be to a huge, lean marten. Its shoulder height was around 12 inches, and its cranium was about 4 inches in length. It had a large body and small legs; however, they were longer than those of the Miacids from which Cynodictis descended.

    Cynodictis was a slender and long-muzzled animal. Its carnassial teeth allowed it to tear off large portions of flesh from dead animals.

    The skull of Cynodictis was also stronger than in previous species, and the dentition was more specialized; the final molars were missing, and the cusps were not as sharp as in Miacids, also a marten-like animal.

    Cynodictis was not the progenitor of modern canids.

    Cynodictis was not the progenitor of modern canids, but its overall morphology suggests it may have served as a forerunner. Because more powerful creodont predators like Hyaenodon and Sarkastodon (a giant wolverine) existed during the same period, the smaller stature of this animal is understandable.

    The Daily Life of a Cynodictis

    Cynodictis’s proportions made it well suited to life on the grassy plains that were spreading throughout Eurasia at the time. But its tiny legs would have let it avoid bigger predators and build deep holes to hide in while hunting smaller food, just like some similarly sized animals do today.

    Where Do You Put Cynodictis?

    It is one of the most ancient and primitive European amphicyonids.

    Important in the development of carnivorous mammals, Cynodictis is represented in the faunas of Late Eocene Europe (particularly in France, Germany, and England). Cynodictis had a body type and proportions comparable to those of ancient Miacids, but it possessed teeth more like those of canids. (Miacids lived between 65.5 and 33.9 million years ago.)

    At first, it was thought that this creature was the ancestor of all dogs and other members of the Canidae family. Cynodictis was one of the oldest members of the amphicyonids (the so-called “beardogs,” long considered to be progenitors of bears), as shown by morphological changes in teeth.

    The distinctiveness and separation of this family from other caniforms were later verified by the discovery of Pseudocyonopsis, Ysengrinia, Amphicyon, and Cynelos.

    On the other hand, true canids like Prohesperocyon first arose in North America around the same time Cynodictis was at its peak in Europe.

    Along with Guangxicyon and the less well-known Brachycyon, Cynodictis is considered one of the most ancient and primitive European amphicyonids. The best-known member of this genus is Cynodictis elegans, which was first discovered in the Late Eocene of France.

    Fossil similarities in teeth imply that this species may also be the origin of the subfamily Haplocyoninae (genera Haplocyon, Haplocyonoides, and Haplocyonopsis), which ultimately gave birth to the American temnocyonines (medium-sized amphicyonids).

    Modern References

    Cynodictis made an appearance in the Walking with Monsters mini-TV series (2005), referred to as “nocturnal predators” and “beardogs”. The nocturnal Cynodictis is captured by an Ambulocetus in the first episode, and a family of Cynodictis emerges in the third episode, cohabitating with an Indricotherium.

    Species

    • Cynodictis cayluxens
    • Cynodictis crassus
    • Cynodictis elegans
    • Cynodictis exilis
    • Cynodictis ferox
    • Cynodictis lacustris
    • Cynodictis longirostris
    • Cynodictis parisiensis
    • Cynodictis peignei
  • Beardog (Amphicyonidae): The Prehistoric Canid Species

    Beardog (Amphicyonidae): The Prehistoric Canid Species

    • Extinct carnivorous family, potential ancestors of caniforms, lived 37-9 million years ago.
    • Ambush hunters with explosive speed, adapted for quick pursuits.
    • Beardogs often specialized in hunting swift, small prey for survival.

    The Amphicyonidae, or beardogs, are a family of extinct carnivorous animals. Some evidence suggests that the Amphicyonidae were the ancestors of all caniforms, despite the fact that they are often thought to be closely related to the Ursidae (bears). About 37 to 9 million years ago, between the Upper Eocene and Upper Miocene, they greatly thrived on Earth. The paws of the beardog were designed for quick, explosive bursts of speed; thus, they likely hunted by ambushing their prey. Similar in size to an American black bear, the beardogs dug subterranean dens in which to rear their young. The weight of a beardog could range from 11 to 1,700 pounds.

    What Exactly Was a Beardog?

    Beardog (Amphicyonidae) artwork.
    Beardog (Amphicyonidae) artwork.

    While the sizes of the beardogs, or Amphicyonidae, were comparable to those of primitive canids, their build was more akin to that of a bear. The majority of these animals walked plantigrade, like bears, with all of their foot bones touching the ground, as opposed to digitigrade, like dogs, whose toe bones simply serve as an extension of the length of the leg, with just the tips touching the ground. However, some paleontologists argue that the Amphicionidae are more closely linked to bears and should be placed in the infraorder Arctoidea rather than the suborder Caniforms (or Caniformia).

    Their Evolution

    Skull of a beardog; specifically of an Amphicyon.
    Skull of a beardog; specifically of an Amphicyon. (Skye McDavid, cc by sa 4.0, cropped)

    Amphicyonids fossils from the genus Simamphicyon are the oldest known, and they date back to the middle of the Eocene, between 40 and 37 million years ago. However, some paleontologists argue that this species should instead be classified as a subfamily within the ancient Miacidae (primitive mammals). Daphoenus (an extinct genus of amphicyonids), whose fossils are dated to the Bartonian (41.2–37.7 Ma) of the Eocene, becomes the earliest representative of the beardogs in this scenario.

    The jaw pieces of an Amphicyon frendens beardog.
    The jaw pieces of an Amphicyon frendens beardog. Source.

    The widespread belief that Amphicyonidae originated in Asia is called into question by the discovery of their fossils in North America. According to another theory, about 45 million years ago, during the middle Eocene, the first beardogs made their initial appearance in North America. However, these species are believed to be a primitive ancestor rather than the actual Amphicyonidae.

    Around 10 million years later, they reached Europe, and another 12 million years later, they expanded to Asia and Africa. Over time, their bodies changed from those of wolves to those of bears, but by the end of the Miocene, they had all but vanished from the face of the earth.

    The range map of beardogs.
    The range map of beardogs. (I do dinosaurs, cc by sa 4.0)

    Still, the earliest known Eurasian representatives of the beardogs, Cynodictis (“slender dog marten”) and Guangxicyon (an extinct genus of amphicyonid that was discovered in southern China), belong to the Priabonian (37.7–33.9 Ma) stage of the Eocene (which was the last age).

    The beardog subfamily Daphoeninae experienced continuous diversification from the end of the Eocene through the Oligocene, and the first representatives of the subfamily Amphicyoninae, including the genera Ysengrinia and Cynelos, migrated into North America during the Rupelian period (33.9–27.8 million years ago).

    Ysengrinia americanus skull. Amphicyonidae subfamily Thaumastocyoninae.
    Ysengrinia americanus skull. Amphicyonidae subfamily Thaumastocyoninae. (Ghedoghedo, cc by sa 4.0)

    The Amphicyonidae family consistently displayed species that weighed around 200 pounds throughout the Oligocene, with the genus Paradaphoenus estimated to weigh around 4 pounds at most.

    The existence of more advanced, earlier-evolved predators like the creodonts Sarkastodon or Hyaenodon, who were excellent hunters of mesonychids, and competition from the Nimravids and Entelodons, which were also effective predators, explains why their sizes were so disappointing. Because of this, beardogs developed a niche hunting strategy focused on tiny, fast-moving prey that the larger predators of the period could not catch.

    The temperature change that marked the end of the Oligocene and the beginning of the Miocene resulted in the decline of forests, the rise of grasslands, and the subsequent rise of herbivore species more suited to extensive migrations. In the face of prehistoric, huge predators, this aided tiny and swift amphicyonids like Amphicyon, Pseudocyon, and Ictiocyon.

    A lower jaw belongs to a species (Pseudocyon sansaniensis) from the Amphicyonidae subfamily Amphicyoninae.
    A lower jaw belongs to a species (Pseudocyon sansaniensis) from the Amphicyonidae subfamily Amphicyoninae. (Ghedoghedo, cc by sa 4.0)

    In addition to other Old World ungulates and small mammals, the arrival of Amphicyonidae in the Lower Miocene through the natural trans-Beringian route shows a lengthy period of faunal interaction between Asia and North America (23 to 16.5 million years ago).

    Between 23.7 and 17.5 million years ago, Daphoenodon and New World temnocyon lived with Old World amphicyonids (Ysengrinia, Amphicyon, Cynelos).

    The earliest progenitors of all living carnivore groups appeared between the end of the Miocene and the start of the Pliocene. The ancestors of today’s wolves, foxes, and other Felidae were not only more intelligent but also had specialized organs for life on the plains and steppes.

    Research on fossilized skulls and brain casts suggests that early species had a lower level of cognitive development than modern carnivores, with more emphasis placed on the senses of smell and sight than on the part of the brain predisposed to problem solving and the emergence of possible social relationships with other species.

    No fossils of beardogs or amphicyonids have been found that would indicate they engaged in pack hunting. It is possible that the extinction of almost all members of the family at the end of the Miocene was predetermined by competition with more effective carnivores and the development of ungulates into quicker and more agile forms. Only Amphicyon seems to have survived until the lower Pliocene in Asia, which is a genus of a beardog subfamily.

    Their Evolutionary Scheme

    Here is the evolutionary scheme of the beardogs (Amphicyonidae).

    Amphicyonidae

    • Simamphicyon helveticus
    • Symplectocyon
    • Vishnucyon
    • Harpagocyon
    • Daphoeninae
      • Daphoenus
        • D. hartshornianus
        • D. lambei
        • D. ruber
        • D. socialis
        • D. transversus
        • D. vetus
      • Paradaphoenus
        • P. cuspigerus
        • P. minimus
        • P. tooheyi
      • Daphoenodon
        • D. falkenbachi
        • D. notionastes
        • D. skinneri
        • D. superbus
        • Borocyon (Daphoenodon)
          • B. neomexicanus
          • B. niobrarensis
          • B. robustum
      • Daphoenictis
        • Brachyrhynchocyon
          • B. dodgei (sin. Daphoenocyon minor)
          • B. intermedius
          • B. montanus
        • Adilophontes
          • A. brachykolos
    • Amphicyoninae
      • Guangxicyon sinoamericanus
      • Euroamphicyon olisiponensis
      • Amphicyanis
      • Brachycyon
        • B. reyi
        • B. palaeolycos
        • B. gaudryi
      • Cynodictis
        • C. elegans
      • Haplocyoninae
        • Haplocyon
          • H. dombrowski
          • H. elegans
          • H. crucians
        • Haplocyonoides
          • H. mordax
          • H. serbiae
          • H. ponticus
        • Haplocyonopsis
      • Temnocyoninae
        • Protemnocyon inflatus
        • Temnocyon
          • T. altigenis
          • T. ferox
          • T. percussor
          • T. typicus
          • T. wallovianus
        • Rudiocyon amplidens
        • Delotrocanter
          • D. petersoni
          • D. oryktes
          • D. major
        • Mammacyon
          • M. obtusidens
          • M. ferocior
      • Pseudamphicyon lupinus
      • Sarcocyon ferox
      • Pseudocyonopsis
        • P. antiquus
        • P. quercensis
        • P. ambiguus
          • Magericyon
            • M. anceps
            • M. castellanus
        • Goupilictis
        • Ysengrinia
          • Y. gerardiana
          • Y. ginsburgi
          • Y. valentiana
          • Y. tolosana
          • Y. depereti
          • Y. americana
        • Thaumastocyon
          • T. dirus
          • T. bourgeoisi
      • Harpagophagus sanguinensis
      • Cynelos
        • C. caroniavorus
        • C. crassidens
        • C. piveteaui
        • C. quercensis
        • C. bohemicus
        • C. helbingi
        • C. lemanensis
        • C. rugosidens
        • C. schlosseri
        • C. sinapius
        • C. idoneus
        • C. euryodon
        • C. macrodon
      • Ictiocyon socialis
        • Pseudarctos bavaricus
      • Pliocyon
        • P. medius
        • P. ossifragus
        • P. robustus
      • Pseudocyon
        • P. sansaniensis
        • P. steinheimensis
        • P. styriacus
        • P. intermedius
      • Arctamphicyon
        • Hubacyon pannonicus
        • Megamphicyon
          • M. giganteus
        • Afrocyon
        • Ischyrocyon gidleyi
          • Hadrocyon mohavensis
        • Agnotherium
          • A. grivense
          • A. antiquus
          • Myacyon
        • Gobicyon
          • G. macrognathus
          • G. zhegalloi
    • Crassidia intermedia
    • Amphicyon
      • A. galushai
      • A. frendens
        • A. ingens
      • A. astrei
      • A. aurelianensis
      • A. caucasicus
      • A. confucianus
      • A. laugnacensis
        • A. lathanicus
        • A. giganteus
      • A. eibiswaldensis
      • A. longiramus
      • A. major
      • A. pontoni
      • A. serus
      • A. styriacus
      • A. reinheimeri
      • A. riggsi
      • A. tairumensis
      • A. ulungurensis
    • “Amphicyon” gutmanni

    Featured Image: DennyNavarra, cc by sa 4.0, cropped.