Talk:Metatheria

"slightly more inclusive group than the marsupials"

What does this group include that is NOT marsupial? I looked at all the groups mentioned at the bottom of the page and all the Wiki pages call them marsupials. Is it purely historical, and now only marsupials are left? --Richardson mcphillips (talk) 00:23, 2 May 2014 (UTC)

Yes, all the metatherians that aren't marsupials are extinct, by definition. Examples of stem metatherians are Sparassodonts, Deltatheroids, and other subgroups marked with a dagger in the taxobox. The box at the bottom of the page lists none of those groups because it's a list of extant mammal orders only. Cephal-odd (talk) 05:49, 4 May 2014 (UTC)

Thanks.--Richardson mcphillips (talk) 05:07, 8 May 2014 (UTC)

Fossil range. Comment to the last anonymous edits.

"Deep time diversity of metatherian mammals: implications for evolutionary history and fossil-record quality". Paleobiology. 44 (2): 171–198. 2018. doi:10.1017/pab.2017.34. {{cite journal}}: Cite uses deprecated parameter |authors= (help)

See page 183: "Early Cretaceous.—It has been proposed that metatherians had diverged from eutherians by the Oxfordian (160 Ma, based on the earliest eutherian fossils and resulting ghost ranges for metatherians [Luo et al. 2011; Williamson et al. 2014]). However, the Jurassic eutherian upon which this view is based has been placed outside of Theria in a recent phylogenetic analysis (Krause et al. 2014). The earliest confirmed metatherian material occurs in the Early Cretaceous of Asia—Sinodelphys szalayi, an exceptionally well-preserved fossil from the Barremian (Luo et al. 2003). This genus is generally regarded as the sister taxon to all other metatherians (Luo et al. 2003, 2011; Vullo et al. 2009; Williamson et al. 2014). Aside from Sinodelphys, the Early Cretaceous record of Metatheria is extremely patchy, consisting only of jaws and teeth from North America (e.g., Cifelli et al. 1998), including remains assignable to Deltatheroida (Kielan-Jaworowska and Cifelli 2001; Davis et al. 2008). This record may reflect genuine low diversity and abundance of the group during its initial radiation."

Late Jurassic (160 Ma) metatherians is speculative assumption, not their fossil range. Earliest known metatheria Sinodelphys szalayi is from Early Cretaceous (ca. 124–131 Ma).

Unregistered User, your edits must be confirmed by references to sources, otherwise they will be rejected as doubtful or wrong! Aleksey (Alnagov (talk) 15:34, 31 December 2018 (UTC))

Hovever, according to new research ("An Early Cretaceous eutherian and the placental–marsupial dichotomy". Nature. 558: 390–395. 2018. doi:10.1038/s41586-018-0210-3. {{cite journal}}: Cite uses deprecated parameter |authors= (help)) Sinodelphys is moved to Eutheria, the sub-clades Deltatheroida and Marsupialiformes, which are both from the Albian (approximately 110 Ma) of western North America are recognized as the oldest known metatherians. Aleksey (Alnagov (talk) 12:42, 6 January 2019 (UTC))

@Alnagov: I was just coming here to make that same comment. I should have read the talk pages earlier and saved time. I have removed Sinodelphys and the Luo et al. (2003) from from the cladogram, which now accurately reflects the source reference (Wilson et al 2016). It might be worth adding a comment about Sinodelphys being reported as most basal metatherian and its reassignment to Eutheria.   Jts1882 | talk  14:29, 25 October 2019 (UTC)