Chronoperates

Chronoperates; Temporal range: Late Paleocene, 55 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	†Symmetrodonta (?)
Family:	†Chronoperatidae; Fox, Youzwyshyn & Krause, 1992
Genus:	†Chronoperates; Fox, Youzwyshyn & Krause, 1992
Type species
	†Chronoperates paradoxus; Fox, Youzwyshyn & Krause, 1992

Chronoperates (meaning "time wanderer" in Greek) is an extinct genus of mammal whose remains have been found in a late Paleocene deposit in Alberta, Canada. It is represented by the type species Chronoperates paradoxus and known only from a partial left lower jaw.^[1] It was first identified in 1992 as a non-mammalian cynodont, implying a ghost lineage of over 100 million years since the previously youngest known record of non-mammalian cynodonts, which at that time was in the Jurassic period (some non-mammalian cynodonts are now known to have persisted until the Early Cretaceous). Subsequent authors have challenged this interpretation, particularly as the teeth do not resemble any known non-mammalian cynodonts. Chronoperates is now generally considered to be more likely to be a late-surviving symmetrodont mammal. This would still infer a ghost lineage for symmetrodonts, but a more plausible one, as symmetrodonts persisted into the Late Cretaceous.

References

^ Fox, Richard C.; Youzwyshyn, Gordon P.; Krause, David W. (1992). "Post-Jurassic mammal-like reptile from the Palaeocene". Nature. 358 (6383): 233–235. Bibcode:1992Natur.358..233F. doi:10.1038/358233a0. PMID 1630490. S2CID 4241895.