Ptolemaia grangeri (P. lyonsi, Osborn 1908; Bown and Simons 1987, Simons and Bown 1995; Oligocene) is a traditional enigma taxon, but nests here with Sinonyx. Ptolemaia shows the extent of the premaxilla and has a tall postparietal.

Masrasector aegypticum (Simons and Gingerich 1974, Miocene, 30 mya) was considered a placental hyaenodont, but here nests with Loxlophus among the marsupials. They were apex predators.

Masrasector nananubis (Borths MR and Seiffert ER 2017; Miocene 30 mya) This skunk-sized predator had huge canine teeth and high jugals with a sagittal crest to anchor large skull muscles.

Didymoconus berkeyi (Matthew WD and Granger W 1924. Gingerich 1981, Wang X et al 2001; IVPP V11983, Eocene 52mya) is a former enigma taxon here nesting with Masrasector. The zygomatic arches are wider posteriorly and the orbits are dorsally open in this phylogenetically miniaturized taxon.

Kerberos langebadreae (Solé et al. 2015; Middle Eocene) was originally described as sister to the marsupial Hyaenodon. Here Kerberos nests with the marsupial Apterodon. The naris is further retracted here and the brow is flatter.

Apterodon macrognathus (Fischer 1880; Eocene to Oligocene, IVPP V 12385) is a member of the Hyaeodontida, a clade within Creodonta, a clade within Marsupialia in the LRT. Here What looks like a carnassial is the anterior of four molars. The premaxilla has two robust teeth. The mandible (dentary) has not retroarticular process in one species, a straight process in another species. Most specimens are from Egypt. The type genus is from Germany.

Borths MR and Seiffert ER 2017. Craniodental and humeral morphology of a new species of Masrasector (Teratodontinae, Hyaenodonta, Placentalia) from the late Eocene of Egypt and locomotor diversity in hyaenodonts. PLoS ONE 12(4):e0173527:1-60.

Bown TM and Simons EL 1987. New Oligocene Ptolemaiidae (Mammalia: ?Pantolesta) from the Jebel Qatrani Formation, Fayum Depression, Egypt. Journal of Vertebrate Paleontology. 7 (3): 311–324.

Cope ED 1881. Mammalia of the lower Eocene beds. American Naturalist 15:337-338.

Fischer P 1880. Note sur un nouveau genre de mammifere fossile (Apterodon gaudryi) des Phosphorites du Quercy. Bulletin de la Société Géologique de France 8: 288-290.

Simons EL and Gingerich PD 1974. New carnivorous mammals from the Oligocene of Egypt. Annals of the Geological Survey of Egypt 4:157-166.

Solé F, Amson E, Borths M, Vidalenc D, Morlo M, Bastl K 2015. A New Large Hyainailourine from the Bartonian of Europe and Its Bearings on the Evolution and Ecology of Massive Hyaenodonts. (Mammalia). PLoS ONE 10(9): e0135698.
doi:10.1371/journal.pone.0135698

Temminck CJ 1824. Monographies de Mammalogie Tom. 1. Paris: Dufour. 60-65..
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wiki/Ptolemaia
wiki/Deltatherium
wiki/Masrasector
wiki/Kerberos
wiki/Apterodon
wiki/Didymoconus