Hoplophoneus
Encyclopedia
Hoplophoneus is an extinct genus
of the family
Nimravidae
, subfamily Nimravinae endemic to North America
during the Late Eocene-Oligocene
epochs (38—33.3 mya), existing for approximately .
by Cope (1874), Simpson (1941), Hough (1949) and Martin (1998).
separated by a septum
with two chambers. Nimravid remains showed no trace of this auditory bulla. Nimravidae had partially cartilaginous bulla and the presence of an ossified bulla with no septum. They also had a flange on the front of the mandible
, not as prominent as those on Thylacosmilus
, that projected downward as long as the canine tooth. Hoplophoneus was structured like the true cat Smilodon
including the saber-like teeth but was about the size of a small leopard
. It had a robust body with shorter legs.
The largest known specimen was examined by Sorkin (2008) for body mass and was estimated to have a weight of 160 kg (352.7 lb).
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Nimravidae
Nimravidae
The Nimravidae, sometimes known as false saber-toothed cats, are an extinct family of mammalian carnivores belonging to the suborder Feliformia and endemic to North America, Europe, and Asia living from the Eocene through the Miocene epochs , existing for approximately .-Morphology:Although some...
, subfamily Nimravinae endemic to North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
during the Late Eocene-Oligocene
Oligocene
The Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...
epochs (38—33.3 mya), existing for approximately .
Taxonomy
Hoplophoneus was named by Cope (1874). It was synonymized subjectively with Drepanodon by Palmer (1904) and Scott and Jepsen (1936). It was assigned to Hoplophoneinae by Flynn and Galiano (1982); to Nimravinae by Bryant (1991); and to NimravidaeNimravidae
The Nimravidae, sometimes known as false saber-toothed cats, are an extinct family of mammalian carnivores belonging to the suborder Feliformia and endemic to North America, Europe, and Asia living from the Eocene through the Miocene epochs , existing for approximately .-Morphology:Although some...
by Cope (1874), Simpson (1941), Hough (1949) and Martin (1998).
Morphology
Hoplophoneus was similar to cats in outward appearance, but the Nimravidae were not true cats. Bone structure was different in the small bones of the inner ear. True cats housed an external structure called an auditory bullaAuditory bulla
The auditory bulla is a hollow bony structure on the ventral, posterior portion of the skull of placental mammals that encloses parts of the middle and inner ear. In most species, it is formed by the tympanic part of the temporal bone.In extant primates, the structure is found in tarsiers,...
separated by a septum
Septum
In anatomy, a septum is a wall, dividing a cavity or structure into smaller ones.-In human anatomy:...
with two chambers. Nimravid remains showed no trace of this auditory bulla. Nimravidae had partially cartilaginous bulla and the presence of an ossified bulla with no septum. They also had a flange on the front of the mandible
Mandible
The mandible pronunciation or inferior maxillary bone forms the lower jaw and holds the lower teeth in place...
, not as prominent as those on Thylacosmilus
Thylacosmilus
Thylacosmilus was a genus of sabre-toothed metatherian predators that first appeared during the Miocene. Remains of the animal have been found in parts of South America, primarily Argentina...
, that projected downward as long as the canine tooth. Hoplophoneus was structured like the true cat Smilodon
Smilodon
Smilodon , often called a saber-toothed cat or saber-toothed tiger, is an extinct genus of machairodonts. This saber-toothed cat was endemic to North America and South America, living from near the beginning through the very end of the Pleistocene epoch .-Etymology:The nickname "saber-tooth" refers...
including the saber-like teeth but was about the size of a small leopard
Leopard
The leopard , Panthera pardus, is a member of the Felidae family and the smallest of the four "big cats" in the genus Panthera, the other three being the tiger, lion, and jaguar. The leopard was once distributed across eastern and southern Asia and Africa, from Siberia to South Africa, but its...
. It had a robust body with shorter legs.