Ichthyoconodon Temporal range: 145–139 Ma |
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Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Subphylum: | Vertebrata |
Class: | Mammalia |
Order: | †Eutriconodonta |
Family: | †Volaticotheria |
Genus: |
†Ichthyoconodon Sigogneau-Russell, 1995 |
Type species | |
Ichthyoconodon jaworowskorum Sigogneau-Russell, 1995 |
Ichthyoconodon is an extinct genus of theriimorph mammal from the Lower Cretaceous of Morocco. Usually considered an eutriconodont, it is notable for its oceanic location and atypical shape, indicative of potentially unusual ecological niches; some researchers think that it may be the first marine mammal, or part of a bizarre clade of gliding mammals.
Ichthyoconodon is known primarily from isolated teeth from Anoual Syncline sediments of Morocco, in particular strata thought to date to the Berriasian. These teeth, mostly molars, possess many synapomorphies associated with volaticotherian eutriconodonts, rather atypical and unique to the clade. The molars are about 4 millimeters long, indicating a size comparable to the related Jugulator.
Ichthyoconodon essentially means "fish cone tooth", from the greek ιχθυς, "fish", κῶνος, "cone", and ὀδών, "tooth". The type species, I. jaworowskorum, was named "in honour of Zofia Kielan-Jaworowska and Zbigniew Jaworowski for their generous hospitality on many occasions".
Ichthyoconodon has been found to be a eutriconodont, though the degree of speciation has been noted as being difficult to assess its status as such. Rose et al. found some skepticism about a eutriconodont identity, and some studies have suggested an identity not even as a mammal, but as a pterosaur, but most recent phylogenetic studies favour a eutriconodont identity.
The most recent phylogenetic studies favour a close relationship with Volaticotherium, Jugulator, Triconolestes and within Volaticotheria. A relationship between it and Volaticotherium has been suggested as far back as the latter's description, albeit not as eutriconodonts.