DOI: 10.5061/dryad.25nt8
title: Data from: The osteology and systematics of the enigmatic Australian Oligo-Miocene metatherian Yalkaparidon (Yalkaparidontidae; Yalkaparidontia; Australidelphia; Marsupialia)

description: We provide the first detailed description of the osteology of the
 enigmatic Oligo-Miocene Australian metatherian Yalkaparidon. This taxon
 exhibits a number of unusual craniodental apomorphies but appears to be
 plesiomorphic within Metatheria in retaining four molars, rather than
 three as previously reported. We demonstrate that the only known skull of
 Yalkaparidon almost certainly represents a single individual. We also
 tentatively refer a number of isolated tarsals to the genus. Maximum
 parsimony analyses of a 258 character morphological matrix (with
 information from the tarsals described here either included or excluded)
 place Yalkaparidon within the superordinal clade Australidelphia, but
 Bayesian analyses of the same matrix are less well resolved, placing
 Yalkaparidon within Marsupialia but without unequivocally supporting
 australidelphian affinities. Bayesian analyses of a total evidence matrix
 that combines the morphological data with 9 kb of sequence data from five
 nuclear protein-coding genes (APOB, BRCA1, IRBP, RAG1 and VWF), 78 indels,
 and 53 retroposon insertion characters are similarly poorly resolved and
 do not clarify the supraordinal relationships of Yalkaparidon beyond
 suggesting that it is probably a member of Marsupialia. However, if the
 tarsal remains are correctly attributed to Yalkaparidon, then membership
 of Australidelphia seems likely, as these specimens exhibit characteristic
 australidelphian apomorphies. We conclude that the ordinal status of
 Yalkaparidon remains justified based on current evidence, and we present a
 revised diagnosis for Yalkaparidontia. We maintain the two currently
 recognized species, Y. coheni and Y. jonesi, but present revised specific
 diagnoses. We suggest a revised phylogenetic definition for Marsupialia,
 and provide phylogenetic definitions for Eomarsupialia (the clade
 comprising all extant Australian marsupial orders) and for the clade
 comprising Dasyuromorphia, Peramelemorphia, and Notoryctemorphia to the
 exclusion of Diprotodontia; we propose the name Agreodontia for the latter
 clade.
description: Yalkaparidon
 morphological matrix - Yalkaparidon scored for craniodental characters
 onlyYalkaparidon
 morphological matrix - Yalkaparidon scored for craniodental characters
 onlyYalk_morph_craniodental_only.nexYalkaparidon morphological matrix - Yalkaparidon scored for craniodental and tarsal charactersYalkaparidon morphological matrix - Yalkaparidon scored for craniodental and tarsal charactersYalk_morph_craniodental_tarsal.nexYalkaparidon total evidence matrix - Yalkaparidon scored for craniodental characters onlyYalkaparidon total evidence matrix - Yalkaparidon scored for craniodental characters onlyYalk_total_craniodental_only.nexYalkaparidon total evidence matrix - Yalkaparidon scored for craniodental and tarsal charactersYalkaparidon total evidence matrix - Yalkaparidon scored for craniodental and tarsal charactersYalk_total_craniodental_tarsal.nex