Ornithorhynchoidea
Superfamily of monotreme mammals
From Wikipedia, the free encyclopedia
Ornithorhynchoidea is a superfamily of egg-laying mammals containing the only living monotremes, the platypus and the echidnas, as well as their closest fossil relatives, to the exclusion of more primitive fossil monotremes of uncertain affinity.[1]
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| Ornithorhynchoids Temporal range: | |
|---|---|
| |
| Two extant ornithorhynchoids: the short-beaked echidna (above) and platypus (below) | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Monotremata |
| Superfamily: | Ornithorhynchoidea Flannery et al., 2024 |
| Families | |
 | |
| Range of extant ornithorhynchoids | |
The clade was defined in 2024 following the discovery of some fossil monotremes from the Late Cretaceous (Cenomanian)-aged Griman Creek Formation of Lightning Ridge Australia, which appeared to be more closely related to extant monotremes than to co-occurring early monotremes such as Steropodon and Kollikodon.[1][2]
Taxonomy
Opalios, the only described member of the extinct family Opalionidae, is considered the most basal ornithorhynchoid due to its unique combination of ancestral and derived traits.[1]
The presence of the probable stem-ornithorhynchids Dharragarra and Patagorhynchus in the Late Cretaceous implies that the divergence between the platypus and echidnas may have occurred during this time.[1] However, genetic estimates tend to prefer a Cenozoic divergence between these two extant groups.[3][4]
Although most members of this group—extinct and extant—are known from Australia, at least two ornithorhynchid-like forms reached southern South America during the Maastrichtian (Patagorhynchus) and early Paleocene (Monotrematum).[5][6]
The following genera are known:
- Superfamily Ornithorhynchoidea Flannery et al., 2024
- Family †Opalionidae Flannery et al., 2024
- Genus †Opalios Flannery et al., 2024
- Family Ornithorhynchidae Gray, 1825
- Genus ?†Dharragarra Flannery et al., 2024
- Genus ?†Monotrematum Pascual et al., 1992
- Genus †Obdurodon Woodburne & Tedford, 1975
- Genus ?†Patagorhynchus Chimento et al., 2023
- Genus Ornithorhynchus Blumenbach, 1800
- Family Tachyglossidae Gill, 1872
- Genus †Megalibgwilia Griffiths, Wells & Barrie, 1991
- Genus †Murrayglossus Flannery et al., 2022
- Genus Tachyglossus Illiger, 1811
- Genus Zaglossus Gill, 1877
- Family †Opalionidae Flannery et al., 2024
They can be distinguished from other fossil monotremes by their twisted-shaped dentaries, with the lingual surfaces being dorsoventrally flattened (aside from in echidnas).[1]
