Morganucodon watsoni from Wales and M. oehleri from China anchor a Lower Jurassic skull comparison with both a squamosal–dentary contact and retained articular–quadrate joint; the anatomy is not a linear transition or direct ancestry claim.
Represented range201.4–145 Ma
Content packagemammal-origins
PBDBtxn:175182
Evidence boundary
Automated checks cover structure, identifiers, translations and links only; maintainer and external expert review are not complete.
Claim ledger
taxonomy · medium
Morganucodontans are sampled as early mammaliaforms outside narrower crown Mammalia in the cited broad character analysis; this placement is a higher-taxon convention and topology, not evidence that Morganucodonta is the direct ancestor of living mammals.
claim:taxon:morganucodonta:taxonomybiogeography · medium
The primary skull study describes Lower Jurassic Morganucodon watsoni from Wales and M. oehleri from China; these two source localities are representative material, not a complete geographic distribution for Morganucodonta.
claim:taxon:morganucodonta:biogeographyecology · medium
The described Morganucodon skulls have teeth differentiated into incisors, canines, premolars and molars, but the study does not directly observe diet, habitat, locomotion or behaviour for Morganucodonta as a whole.
claim:taxon:morganucodonta:ecologymorphology · high
Kermack and colleagues describe a 26 mm Morganucodon watsoni skull and a slightly larger M. oehleri skull, with a squamosal–dentary contact while the articular–quadrate joint is retained; this is one anatomical mosaic, not a linear transition or direct ancestry claim.
claim:taxon:morganucodonta:morphologyfossil-range · medium
Morganucodonta is displayed at 201.4–145 Ma only as the synthesis's sampled fossil envelope, not exact global genus-group endpoints. The interval is a source-bounded sample window, not a global FAD, LAD, divergence date, continuous occupancy claim or direct-ancestor assertion.