| Diamantofelis Temporal range: Late Burdigalian | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Carnivora |
| Suborder: | Feliformia |
| Family: | Felidae |
| Genus: | † Diamantofelis Morales et al., 1998 |
| Type species | |
| †Diamantofelis ferox Morales et al., 1998 | |
Diamantofelis is an extinct genus of felids that lived in what is now Namibia during the Early Miocene. It contains a single species, Diamantofelis ferox. [1] [2]
This genus was described in 1998 on the basis of remains discovered at the locality of Arrisdrift in Namibia, which has variously been dated to 17.5 Ma [3] or 16 Ma. [4] The holotype (AD 98'95), is a left mandible which includes the canine and cheek teeth. [1] In 2003 various postcranial remains belonging to this genus were described. These include the first phalanx (AD 601'99) as well as the proximal end of a left ulna (AD 112'94) Furthermore, the fragments of another ulna (AM 2'99), found at the slightly older locality Auchas, which dates to ca. 19 Ma, were referred to Diamantofelis. [2]
A second species named Diamantofelis minor was originally described from the same locality, but has since been moved to the genus Namafelis . [2] These two genera are notable for being the first, and until the description of Asilifelis in 2012 the only, [5] known felid remains from the lower Miocene of Africa.
It is named after the Diamond Area 1, where the fossils were found. The specific name ferox translates to “fierce”. [1]
Diamantofelis is the largest felid known from the Early Miocene of Africa. Its size has been described as slightly smaller than a cheetah, [1] and as comparable to a small cougar. [6]
It possesses a very robust mandible, with a short horizontal ramus and a masseteric fossa which does not reach the level of m1 talonid. Its diastema is short and its articulation strong and covered in heavy rugosities. Its canine is sub-rounded in transverse section, with a relatively low crown possessing two sharp crests, in posterior and anterior position, respectively. The cheek dentition is very sectorial, with elongated and narrow premolars and carnassial. The p1 [7] and p2 are absent. The central cuspid of the p3 is high, while the anterior and posterior ones are lower and smaller. A moderate posterior cingulum borders the posterior accessory cusplet. Both the labial and lingual cingula are smooth. Its p4 is also narrow, and very-high crowned, with well-developed accessory cuspids. [7] The m1 is damaged, lacking the top of the paraconid and the lingual part of the protonocid. Regardless, it can be determined that it possessed a rather high paraconid with a small anterobasal expansion. Just anterior to the very short talonid is a low inflection in the buccal enamel surface, corresponding to the base of a small metaconid. In comparison to Pseudaelurus , its mandible and diastema are much shorter, while its premolars and m1 are much narrower and higher. [1] Among felids, species with short jaws take proportionally smaller prey than those with longer jaws, as the length of the jaw determines the gape distance, and therefore the size of the prey that fits within their canine teeth. [8]
The mandibular proportions showcase that its head already looked rounded and cat-like, with a shortened muzzle and hypercarnivorous dentition. [9]
Only fragmentary postcranial materials are known from this genus. Its first phalanx is slightly larger than that of the Iberian Lynx, but its morphology is practically identical otherwise. The proximal end of its left ulna is of rectangular shape and elongated anteroposteriorly. The olecranon tuberosity is formed by the widened and rugose posterior margin. A central groove is developed in the anterior half of the proximal surface, and, a bit more medially advanced, similar sized swellings are developed on its anterolateral and anteromedial vertices. A central narrowing is found on the anterior surface, between the proximal surface and the anconeal process, which is similar to that seen in other felids. Just like in these forms, the anterior border is not curved except that its proximo-distal axis is parallel to the same axis of the bone. A distally marked curve is created by the margin of this process. Located below the anconeal process, the trochlear notch is very concave and slightly medially inclined. In comparison to similar-sized felids, the latero-medial width is proportionally slimmer. A small, distally curving swelling that can develop on the antero-distal margin of the trochlear notch can develop in various felids, but this condition is not found in Diamantofelis. Other resemblances it has with extant felids is the roughened posterior margin of the proximal end, which narrows distally and leans slightly medially, and the antero-distal margin of the trochlear notch, which overhangs the antero-proximial end. A lateral tubercle is located slightly below the middle in its proximal margin and its proximal end is straight. Both the semicircular lateral surface of the anconeal process and a shallow trochlear notch are developed on the anterior border. It possesses a high and rather straight olecranon process. Both the medial and lateral surface of the proximal end have a rough surface, although a clear crest is developed on the postero-proximal margin of the medial side. Its diaphysis is medio-laterally compressed and is almost straight. The ulna from Auchas is similar, although larger and in possession of a more massive and broader olecranon process. The tuberosities of the ulna's antero-proximal border can be used to determine some biomechanical aspects of carnivorans. As the adaptions of Diamantofelis are very similar to those of the margay, it can be deduced to have been a forest-dwelling cat with weak cursorial abilities. [2]
Except for its close relationship to Namafelis, the affinities of Diamantofelis are not well-understood. [10] It is clearly not particularly closely related to Asilifelis or Katifelis , the other Early Miocene felids from Africa, which possessed comparatively advanced dental characteristics. Indeed, it has been suggested that Asilifelis originates from a different dispersal event into Africa altogether. Its features are of “Pseudaelurus-grade”, suggesting it is more basal than machairodontines and felines, and its dental features match those of European pseudaelurines. [5] Similarities to the barbourofelid Afrosmilus , which was originally considered to have been a feline, have been noted since its original description. [1] As such, possible barbourofelid affinities have been proposed. [5] Nowadays, they are usually considered felids. [7] [10] [11] Similarly, the assignment of the Afrosmilini to the barbourofelids has also been questioned, and it has been suggested that they were possibly felids closely related to Diamantofelis and Namafelis after all. [11]
The locality of Arrisdrift likely represents a side channel of the Proto-Orange River, which was only occasionally filled with flowing water, perhaps when the river overflowed during the rainy season. The rest of the time it was a shallow pool. The presence of 'Crocodylus' gariepensis and giant tortoises indicate a more tropical climate than found in the area today. [9] The habitat was likely a bushy, rather wooded savanna, with a gallery-forest along the river. [12]
Diamantofelis shared its habitat with its smaller relative Namafelis minor, as well as other small and medium-sized carnivorans – the viverrid Orangictis gariepensis , the stenoplesicitid Africanictis meini , the large mustelid Namibictis senuti and the hyainailourid Buhakia hyaenoides . [13] The largest predators of Arrisdrift were the bear-dogs Namibiocyon ginsburgi [14] and Amphicyon giganteus , and the hyaenodont Hyainailouros sulzeri. Diamantofelis likely preyed on the smaller animals of this faunal assemblage, such as the macroscelidid Myohyrax , the springhare Megapedetes , the lagomorph Australagomys or various birds and rodents. Somewhat larger prey possibly included the small bovid Namacerus or young of the large hyrax Prohyrax . [1] [9] Other inhabitants include the small suids Namachoerus and Nguruwe, [15] the tragulid Dorcatherium , [16] the climatoceratid Orangemeryx, [17] the diminutive aardvark Myorycteropus [18] [19] and the proboscidea Afromastodon and Prodeinotherium . [20]
The ulna or ulnar bone is a long bone in the forearm stretching from the elbow to the wrist. It is on the same side of the forearm as the little finger, running parallel to the radius, the forearm's other long bone. Longer and thinner than the radius, the ulna is considered to be the smaller long bone of the lower arm. The corresponding bone in the lower leg is the fibula.
The humerus is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a rounded head, a narrow neck, and two short processes. The body is cylindrical in its upper portion, and more prismatic below. The lower extremity consists of 2 epicondyles, 2 processes, and 3 fossae. As well as its true anatomical neck, the constriction below the greater and lesser tubercles of the humerus is referred to as its surgical neck due to its tendency to fracture, thus often becoming the focus of surgeons.
The forearm is the region of the upper limb between the elbow and the wrist. The term forearm is used in anatomy to distinguish it from the arm, a word which is used to describe the entire appendage of the upper limb, but which in anatomy, technically, means only the region of the upper arm, whereas the lower "arm" is called the forearm. It is homologous to the region of the leg that lies between the knee and the ankle joints, the crus.
The fibula or calf bone is a leg bone on the lateral side of the tibia, to which it is connected above and below. It is the smaller of the two bones and, in proportion to its length, the most slender of all the long bones. Its upper extremity is small, placed toward the back of the head of the tibia, below the knee joint and excluded from the formation of this joint. Its lower extremity inclines a little forward, so as to be on a plane anterior to that of the upper end; it projects below the tibia and forms the lateral part of the ankle joint.
The radius or radial bone is one of the two large bones of the forearm, the other being the ulna. It extends from the lateral side of the elbow to the thumb side of the wrist and runs parallel to the ulna. The ulna is longer than the radius, but the radius is thicker. The radius is a long bone, prism-shaped and slightly curved longitudinally.
The ulnar collateral ligament (UCL) or internal lateral ligament is a thick triangular ligament at the medial aspect of the elbow uniting the distal aspect of the humerus to the proximal aspect of the ulna.
The olecranon, is a large, thick, curved bony eminence of the ulna, a long bone in the forearm that projects behind the elbow. It forms the most pointed portion of the elbow and is opposite to the cubital fossa or elbow pit. The olecranon serves as a lever for the extensor muscles that straighten the elbow joint.
In the human arm, the humeral trochlea is the medial portion of the articular surface of the elbow joint which articulates with the trochlear notch on the ulna in the forearm.
Barbourofelidae is an extinct family of carnivorans of the suborder Feliformia, sometimes known as false saber-toothed cats, that lived in North America, Eurasia and Africa during the Miocene epoch and existed for about 7.9 million years. Thought to be an independent lineage from the Nimravidae and Machairodontinae, which had all attained elongated canines, recent research argues that it may be a subfamily of the Nimravidae, extending its biochronological range into the Miocene, although this issue is not yet fully resolved.
The elbow is the region between the upper arm and the forearm that surrounds the elbow joint. The elbow includes prominent landmarks such as the olecranon, the cubital fossa, and the lateral and the medial epicondyles of the humerus. The elbow joint is a hinge joint between the arm and the forearm; more specifically between the humerus in the upper arm and the radius and ulna in the forearm which allows the forearm and hand to be moved towards and away from the body. The term elbow is specifically used for humans and other primates, and in other vertebrates forelimb plus joint is used.
A supracondylar humerus fracture is a fracture of the distal humerus just above the elbow joint. The fracture is usually transverse or oblique and above the medial and lateral condyles and epicondyles. This fracture pattern is relatively rare in adults, but is the most common type of elbow fracture in children. In children, many of these fractures are non-displaced and can be treated with casting. Some are angulated or displaced and are best treated with surgery. In children, most of these fractures can be treated effectively with expectation for full recovery. Some of these injuries can be complicated by poor healing or by associated blood vessel or nerve injuries with serious complications.
Ysengrinia is an extinct genus of carnivoran in the family Amphicyonidae (beardogs), which lived in Europe, Asia, and North America during the Early Miocene. It was also reported from Egypt and Namibia, but this material has been reassigned to other genera of beardogs.
Allodelphinidae is a family of primitive platanistoid river dolphins found in marine deposits in the eastern North Pacific region, Alaska, and Japan.
Zhongjianosaurus is a genus of dromaeosaurid belonging to the Microraptoria. Believed to hail from the Yixian Formation, specifically the middle of the Jehol Biota, it is the smallest known microraptorine thus far discovered and one of the smallest non-avian theropod dinosaurs.
Exiguodon is an extinct genus of hyainailourid hyaenodont mammal of the subfamily Hyainailourinae. Remains are known from early Miocene deposits in Kenya and Uganda, in East Africa.
Asilifelis is an extinct genus of small felid that lived in what is now Kenya during the Early Miocene. Despite its fragmentary remains, it is remarkable because of its small size and advanced dentition. It contains a single species, Asilifelis cotae.
Katifelis is an extinct genus of felids that lived in what is now Kenya during the Early Miocene and is notable for its dental features, which are intermediate between basal and modern cats. It contains a single species, Katifelis nightingalei.
Namafelis is an extinct genus of felids that lived in what is now Namibia during the Early Miocene. It contains a single species, Namafelis minor. Closely related to Diamantofelis, it is of “Pseudaelurus-grade”, and therefore a rather basal member of the cat family.
Myacyon is an extinct genus of large sized carnivoran mammals, belonging to the family Amphicyonidae, that lived in Africa during the Miocene epoch. Due to the limited scope and fragmentary nature of the severely damaged holotype, as well as the illustrations in its descriptions, which have been called inadequate, usage of this genus poses serious issues. However, it is notable for being one of the last surviving members of its family and its adaptions to hypercarnivory. Its relationships to other amphicyonids are obscure, and it is not closely related to Bonisicyon, the other late surviving African genus, although it has been proposed that it descends from a species of Cynelos or Namibiocyon.
Namibiocyon is an extinct genus of carnivoran mammals, belonging to the family Amphicyonidae, that lived in Namibia during the Early Miocene epoch. Before the erection of this taxon in 2022, the type and only species, N. ginsburgi, had been assigned to a variety of other genera. It is notable for its adaptions toward hypercarnivory.
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