Steropodontidae is an extinct family of early monotreme mammals known from the Cretaceous of Australia.

Steropodontids
Temporal range: Late Cretaceous (Cenomanian), 100.2–96.6 Ma
Steropodon dentary
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Monotremata
Family: Steropodontidae
Archer, Flannery, Ritchie, & Jones, 1995
Type genus
Steropodon
Archer, Flannery, Ritchie, & Molnar, 1985
Genera

Taxonomy

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Steropodon was initially placed in the crown group monotreme family Ornithorhynchidae but was subsequently made the type genus of Steropodontidae, its own monotypic family.[1] The monotreme Teinolophos was suggested to also belong in this family,[2] before also being placed in a distinct family.[3] Parvopalus, known from the same locality as Steropodon, may be a steropodontid.[4]

Description

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Steropodontids are small monotremes; Steropodon has an estimated body mass of 2 kilograms (4.4 lb), and Parvopalus represents the smallest mammal found in its faunal assemblage. Members of this clade are characterized by having narrow and tall dentaries compared to other monotremes, and a prominent ascending ramus of the dentary.[4]

References

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  1. ^ Flannery, Timothy F.; Archer, Michael; Rich, Thomas H. & Jones, Robert (1995). "A new family of monotremes from the Cretaceous of Australia". Nature. 377 (6548): 418–420. doi:10.1038/377418a0. S2CID 4301982.
  2. ^ Rich, Thomas H.; Vickers-Rich, Patricia; Trusler, Peter; Flannery, Timothy F.; Cifelli, Richard; Constantine, Andrew; Kool, Lesley; Van Klaveren, Nicholas (February 2001). "Monotreme nature of the Australian Early Cretaceous mammal Teinolophos". Acta Palaeontologica Polonica. 46 (1): 113–118.
  3. ^ Flannery, Timothy F.; Rich, Thomas H.; Vickers-Rich, Patricia; Ziegler, Tim; Veatch, E. Grace; Helgen, Kristofer M. (2022-01-02). "A review of monotreme (Monotremata) evolution". Alcheringa: An Australasian Journal of Palaeontology. 46 (1): 3–20. doi:10.1080/03115518.2022.2025900. ISSN 0311-5518.
  4. ^ a b Flannery, Timothy F.; McCurry, Matthew R.; Rich, Thomas H.; Vickers-Rich, Patricia; Smith, Elizabeth T.; Helgen, Kristofer M. (2024-05-26). "A diverse assemblage of monotremes (Monotremata) from the Cenomanian Lightning Ridge fauna of New South Wales, Australia". Alcheringa: An Australasian Journal of Palaeontology. 48 (2): 319–337. doi:10.1080/03115518.2024.2348753. ISSN 0311-5518.