Cimolestidae, sensu McKenna and Bell, 1997

Wible, JR, Rougier, GW, Novacek, MJ & Asher, RJ, 2009, The Eutherian Mammal Maelestes Gobiensis From The Late Cretaceous Of Mongolia And The Phylogeny Of Cretaceous Eutheria, Bulletin of the American Museum of Natural History 2009 (327), pp. 1-123 : 63-64

Cimolestidae + Asioryctitheria

Wible et al. (2007) allied cimolestids and asioryctitheres (fig. 29: M), a grouping with some resemblance to the Palaeoryctidae of Kielan-Jaworowska et al. (1979), which included the Mesozoic genera Cimolestes , Batodon , Asioryctes , and Procerberus (now generally considered to be an early Paleocene taxon, Kielan-Jaworowska et al., 2004). Cimolestidae and Asioryctitheria are united by eight synapomorphies (appendix 4: node M): upper molar (M2) metacone noticeably smaller than paracone (character 77; fig. 33), and metacone and paracone bases adjoined (character 79; fig. 33); lower molar (m2) talonid narrower than trigonid (character 119; fig. 34); minor palatine foramen with pterygoid contribution (character 194); frontal length on midline less than half that of parietal (character 226); fossa incudis anteri- or to level of fenestra vestibuli (character 296; fig. 36; also in Zalambdalestes ); hypoglossal foramen housed in opening larger than jugular foramen (character 315; fig. 36); and petrosal roof for external acoustic meatus (character 321; fig. 36). The distribution of the four cranial synapomorphies can be ascertained only in Maelestes , Kennalestes (unknown for character 226), Asioryctes , Ukhaatherium , and Uchkudukodon (unknown for characters 315 and 321).

Maelestes further resembles Uchkudukodon , Kennalestes , Asioryctes , and Ukhaatherium in having a minor palatine foramen with a narrow posterior bridge, a groove connecting the sphenopalatine and maxillary foramina, a midline crest in basipharyngeal canal (fig. 36), and a medial flange of the petrosal (fig. 36). Maelestes resembles the Uzbekistani clade ( Bulaklestes , Daulestes , and Uchkudukodon ) in the presence of a labial mandibular foramen, the position of the posterior end of the palate anterior to the last molar, a vestigial zygomatic process of the maxilla, and a transpromontorial internal carotid artery; the distribution of the last three features is known only for Uchkudukodon among the Uzbekistani taxa. On the other hand, Maelestes resembles the Mongolian clade ( Kennalestes , Asioryctes , and Ukhaatherium ) in having an ectopterygoid process and an elliptical oval window; the ectopterygoid process is lacking and the oval window more rounded in Uchkudukodon ( McKenna et al., 2000) . Maelestes resembles the Mongolian clade (and Zalambdalestes and Barunlestes ) in an additional five features whose distribution is unknown in the Uzbekistani clade: a piriform fenestra; a notched caudal tympanic process; a tympanic process of Kielan-Jaworowska (1981); crista interfenestralis and caudal tympanic process of the petrosal connected by a curved ridge (fig. 36), and a post-promontorial tympanic sinus in the same horizontal plane as the cochlear fossula. Lastly, Maelestes resembles Ukhaatherium and probably Asioryctes (Kielan- Jaworowska, 1981: 39) in having a carotid foramen in the basisphenoid, whereas this aperture is between the petrosal and basisphenoid in Uchkudukodon ( McKenna et al., 2000) .

Maelestes differs from asioryctitheres in having: a single-rooted lower canine (except in Ukhaatherium, Novacek et al., 1997 ); five upper and lower premolars (except in juvenile Kennalestes , which has five upper premolars, Kielan-Jaworowska, 1981); three subequal, procumbent lower incisors; no condylar peduncle on the dentary; a mandibluar condyle more than a molar length dorsal to the occlusal plane; two lacrimal foramina; a palatal vacuity between the maxilla and palatine; maxillary foramen without palatine contribution; midline rod-shaped eminence on the basisphenoid (fig. 36); a glenoid fossa partly on the braincase (fig. 36); a postglenoid foramen behind the postglenoid process (fig. 36); a small prootic canal; no mastoid foramina in the mastoid exposure (unknown in Uchkudukodon ); and a posttemporal canal. In the postcranial elements preserved, Maelestes is similar to Ukhaatherium , the asioryctithere with the most completely preserved skeleton ( Horovitz, 2000, 2003), except that in the former the cranial articular foveae and dens of the axis are not linked and the humerus has a supratrochlear foramen.