Hyainailouridae

Hyainailouridae ("hyena-cats") is a paraphyletic family of extinct predatory mammals from extinct paraphyletic superfamily Hyainailouroidea within extinct order Hyaenodonta. Hyaenodontids arose during the middle Eocene and persisted well into the middle Miocene. Fossils of this group have been found in Asia, Africa, North America and Europe.
General characteristics
Hyainailourids are characterized by long skulls, slender jaws, slim bodies, and a plantigrade stance. They generally ranged in size from 30 to 140 cm at the shoulder. While some measured as much as 1.4 m high at the shoulder with head-body length up to 3.2 m and weighed up to 1,500 kg, most were in the 5–15 kg range, equivalent to a mid-sized dog. The anatomy of their skulls show that they had a particularly acute sense of smell, while their teeth were adapted for shearing, rather than crushing.
At least one hyainailourid lineage, Apterodontinae, was specialised for aquatic, otter-like habits.
Range
The oldest member of the Hyainailouridae is Orienspterodon from the middle Eocene of China. They were important hypercarnivores in Eurasia and Africa during the Oligocene, but gradually declined, with almost the entire family becoming extinct by the close of the Oligocene. Only Simbakubwa, Megistotherium and several of its sister genera, including Hyainailouros and Sivapterodon, survived into the Miocene. Traditionally this has been attributed to competition with carnivorans, but no formal examination of the correlation between the decline of hyaenodontids and the expansion of carnivorans has been recorded, and the latter may simply have moved into vacant niches after the extinction of hyaenodontid species.
Classification and phylogeny
Relations
Hyainailouridae used to be considered a subfamily of Hyaenodontidae, but cladistic study by Sole et al., (2013, 2015) treats it as a distinct family. Two subfamilies are recognized, Apterodontinae and paraphyletic Hyainailourinae.
Taxonomy
Family: †Hyainailouridae (paraphyletic family)
(unranked): †Maocyon/Orienspterodon clade
Genus: †Maocyon
†Maocyon peregrinus
Genus: †Orienspterodon
†Orienspterodon dahkoensis
Subfamily: †Apterodontinae
Genus: †Apterodon
†Apterodon altidens
†Apterodon gaudryi
†Apterodon langebadreae
†Apterodon macrognathus
†Apterodon rauenbergensis
†Apterodon saghensis
†Apterodon sp. [Dur At-Talah escarpment, Libya]
Genus: †Quasiapterodon
†Quasiapterodon minutus
Subfamily: †Hyainailourinae (paraphyletic subfamily)
Genus: †Megistotherium
†Megistotherium osteothlastes
Genus: †Mlanyama
†Mlanyama sugu
Genus: †Pakakali
†Pakakali rukwaensis
Genus: †Simbakubwa
†Simbakubwa kutokaafrika
(unranked): †Akhnatenavus clade
Genus: †Akhnatenavus
†Akhnatenavus leptognathus
†Akhnatenavus nefertiticyon
Genus: †Hemipsalodon
†Hemipsalodon grandis
†Hemipsalodon viejaensis
Genus: †Ischnognathus
†Ischnognathus savagei
Tribe: †Hyainailourini (polyphyletic tribe)
Genus: †Exiguodon
†Exiguodon pilgrimi
Genus: †Falcatodon
†Falcatodon schlosseri
Genus: †Hyainailouros (polyphyletic genus)
†Hyainailouros bugtiensis
†Hyainailouros napakensis
†Hyainailouros sulzeri
Genus: †Parapterodon
†Parapterodon lostangensis
Genus: †Sectisodon
†Sectisodon markgrafi
†Sectisodon occultus
Genus: †Sivapterodon
†Sivapterodon lahirii
Subtribe: †Isohyaenodontina (polyphyletic subtribe)
Genus: †Isohyaenodon (polyphyletic genus)
†Isohyaenodon andrewsi
†Isohyaenodon zadoki
(unranked): †Pterodon clade
Genus: †Kerberos
†Kerberos langebadreae
Subtribe: †Pterodontina
Genus: †Pterodon
†Pterodon dasyuroides
Incertae sedis:
†"Pterodon" syrtos
Incertae sedis:
†"Pterodon" africanus
†"Pterodon" phiomensis
†"Pterodon" sp. [DPC 5036]
Tribe: †Leakitheriini
Genus: †Leakitherium
†Leakitherium hiwegi
Tribe: †Metapterodontini
Genus: †Metapterodon
†Metapterodon brachycephalus
†Metapterodon kaiseri
†Metapterodon stromeri
Tribe: †Paroxyaenini
Genus: †Paroxyaena
†Paroxyaena galliae
†Paroxyaena pavlovi
Incertae sedis:
†"Pterodon" sp. [BC 15’08]
†Hyainailourinae sp. [GSN AD 100’96]
†Hyainailourinae sp. [UON 84-359]
†Hyainailourinae sp. A [DPC 6555]
†Hyainailourinae sp. C [DPC 9243 & DPC 10315]
†Hyainailourinae sp. D [DPC 6545]
Phylogeny
The phylogenetic relationships of family Hyainailouridae are shown in the following cladogram:
See also
Mammal classification
Hyainailouroidea
References
Hyaenodonts
Eocene mammals
Oligocene mammals
Miocene mammals
Prehistoric mammal families