SARCODONTIDAE, Lopatin and Kondrashov, 2004

Ting, Suyin, Wang, Xiaoming & Meng, Jin, 2023, Cranial And Postcranial Morphology Of The Insectivoran-Grade Mammals Hsiangolestes And Naranius (Mammalia, Eutheria) With Analyses Of Their Phylogenetic Relationships, Bulletin of the American Museum of Natural History 2023 (463), pp. 1-129 : 101-102

SARCODONTIDAE

Our cladistic analysis on the 36 terminal taxa with over 290 cranial and dental characters (fig. 56: node 62) supports the monophyletic clade of Sarcodontidae , including Hsiangolestes , Sinosinopa , Prosarcodon , and Sarcodon . Monophyly of the family is well supported by several cranial (chars. 134, 224, 242) and dental (1, 9, 56, 73, 74, 112, 114) synapomorphies, and supported by 100% of shortest tree discovered by TNT. In the majority rule tree, Hsiangolestes is in an Asian clade, with three other Asian genera, Sinosinopa , Prosarcodon , and Sarcodon (fig. 56: node 62). Three cranial synapomorphies, coronoid process width (char. 134), foramen ovale composition (char. 224), and basisphenoid tympanic process (char. 242), are unknown (coded as missing) in Sinosinopa , Prosarcodon , and Sarcodon . Number of postcanine tooth (char. 1), number of lower incisor (char. 9), and M1 width (char. 73) in Sarcodon , M1 width (char. 73) and M2 parastyle and metastyle lobe labial extension (char. 74) in Prosarcodon , and number of lower incisor (char. 9) and diastema posterior to p2 (char. 56) in Sinosinopa are unknown. Hsiangolestes has several autamorphies: I1 subequal to I 2 in size (char. 6), presence of a diastema posterior to P2 (char. 30), P3 paracone greatly enlarged (char. 32), P4 less asymmetrical (char. 48), p3 subequal to p 2 in size (char. 57), p3 protoconid subequal to that of p4 (char. 58), paracrista weak (char. 85), protocristid transversely situated (char. 116), talonid multicuspid basined (char. 118), internal carotid artery course transpromontorial (char. 245), and fenestra cochlear posteromedially situated to fenestra vestibule (char. 264).

Hsiangolestes was first identified as a didymoconid ( Zheng and Huang, 1984), and was later assigned to Cimolesta ( McKenna and Bell, 1997) and Lipotyphla ( Lopatin and Kondrashov, 2004; Lopatin, 2006) respectively. Our study indicates that Hsiangolestes is neither related to our redefined Cimolestidae ( Cimolestes + Naranius ; see Phylogenetic Analysis below) nor to Lipotyphla as McKenna and Bell (1997) and Lopatin (2006) suggested. We assigned Hsiangolestes to the new family Sarcodontidae , order incertae sedis. In the majority rule tree (fig. 56: node 70), Hsiangolestes is sister to Sinosinopa - Prosarcodon - Sarcodon . This clade is supported by seven dental synapomorphies (chars. 23, 42, 47, 66, 99, 113, 125). Absence of P3 protocone (char. 33), not well-developed protocone on P4 (char. 39), and P4 less asymmetrical (char. 48) in Hsiangolestes shows less-molariform premolar, which indicates that Hsiangolestes is more primitive. Morphologically, the dentition of