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

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 ''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)}
** Subfamily: †Apterodontinae
*** Genus: †'' Apterodon''
**** †''Apterodon altidens''
**** †''Apterodon gaudryi''
**** †''Apterodon langebadreae''
**** †''Apterodon macrognathus''
**** †''Apterodon rauenbergensis''
**** †''Apterodon saghensis''
**** †''Apterodon'' sp. ur At-Talah escarpment, Libya
*** Genus: †'' Quasiapterodon''
**** †''Quasiapterodon minutus''
** Subfamily: †Hyainailourinae ^{(paraphyletic subfamily)}
*** Genus: †''Megistotherium''
**** †''Megistotherium osteothlastes''
*** Genus: †'' Mlanyama''
**** †''Mlanyama sugu''
*** Genus: †''Orienspterodon''
**** †''Orienspterodon dahkoensis''
*** 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:

References

{{Taxonbar, from=Q34463943

Hyaenodonts
Eocene mammals
Oligocene mammals
Miocene mammals
Prehistoric mammal families