Ornithorhynchidae

Ornithorhynchidae Temporal range: Early Paleocene to Present, 61–0 Ma PreЄ Є O S D C P T J K Pg N
Platypus
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Synapsida
Class:	Mammalia
Order:	Monotremata
Suborder:	Platypoda
Family:	Ornithorhynchidae Gray, 1825
Genera
†Obdurodon Ornithorhynchus

The Ornithorhynchidae are one of the two extant families in the order Monotremata, and contains the platypus and its extinct relatives. The other family is the Tachyglossidae, or echidnas. Within Ornithorhynchidae are two genera, Obdurodon and Ornithorhynchus:

• Family Ornithorhynchidae
  • Genus †Obdurodon — an ancient branch of the platypus family
    • †Obdurodon dicksoni
    • †Obdurodon insignis
    • †Obdurodon/Monotrematum sudamericanum
    • †Obdurodon tharalkooschild
  • Genus Ornithorhynchus
    • Ornithorhynchus anatinus (the modern platypus)

Another two genera, Steropodon and Teinolophos, were originally thought to belong to Ornithorhynchidae. However, they were both placed into a new family, Steropodontidae.^[1] This decision was made based on differences in the dentary recovered from the Griman Creek Formation, Lightning Ridge, New South Wales, Australia. This dentary is the holotype for the Steropodon genus, and thus the lack of information is what led to the original misclassification. Further research on Teinolophos has indeed shown it to be an animal much different from ornithochrynchids, lacking a beak, possessing a more complete mammalian dentition and retaining primitive ears connected to the jaw as in more basal mammals.^[2]

The extinct Ornithorhynchus maximus was once included in Ornithorhynchus, but has now been determined to be from the echidna family as Zaglossus robustus.^[3]

References

1. Flannery, Timothy F.; Archer, Michael; Rich, Thomas H.; Jones, Robert (5 October 1995). "A new family of monotremes from the Creataceous of Australia". Nature. 377: 418–420. doi:10.1038/377418a0.
2. Thomas H. Rich, James A. Hopson, Pamela G. Gill, Peter Trusler, Sally Rogers-Davidson, Steve Morton, Richard L. Cifelli, David Pickering, Lesley Kool, Karen Siu, Flame A. Burgmann, Tim Senden, Alistair R. Evans, Barbara E. Wagstaff, Doris Seegets-Villiers, Ian J. Corfe, Timothy F. Flannery, Ken Walker, Anne M. Musser, Michael Archer, Rebecca Pian and Patricia Vickers-Rich (2016). "The mandible and dentition of the Early Cretaceous monotreme Teinolophos trusleri". Alcheringa: An Australasian Journal of Palaeontology. in press. doi:10.1080/03115518.2016.1180034.
3. Musser, A. M. (2003). "Review of the monotreme fossil record and comparison of palaeontological and molecular data". Comparative Biochemistry and Physiology A. 136 (4): 927–42. doi:10.1016/s1095-6433(03)00275-7. PMID 14667856.

Media related to Ornithorhynchidae at Wikimedia Commons

• Groves, C.P. (2005). Wilson, D.E.; Reeder, D.M., eds. Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Baltimore: Johns Hopkins University Press. p. 2. OCLC 62265494. ISBN 0-801-88221-4.