The Creodonta revisited in the LRT

Keep in mind the concept of convergence
whenever reviewing purported members of the Creodonta. Several purported creodonts have been added to the large reptile tree (LRT, 1342 taxa) recently.

According to Wikipedia,
“Creodonts were the dominant carnivorous mammals from 55 to 35 million years ago, peaking in diversity and prevalence during the Eocene.”

McKenna1975 considered the Creodonta
the sister taxa to the Carnivora within the clade Ferae (Carnivora + Pholidota (= pangolins)). The LRT finds pretty much the same relationship, but with creodonts on the marsupial side of the node and carnivores on the placental side of the node. The arboreal didelphid Caluromys is the only taxon that nests between marsupial creodonts and placental carnivores at present. (In the LRT pangolins nest with currently dissimilar bats. Ancestors of both, Chriacus and Zhangheotherium were much more similar.)

Halliday et al. 2015 nested creodonts
as sisters to pangolins in a cladogram that bore little to no resemblance to the LRT.

Figure 1. Oxyaena, a traditional creodont. This is a cat-like member of the carnivorous Marsupialia.

Figure 1. Oxyaena, a traditional creodont. This is a cat-like member of the carnivorous Marsupialia.

According to Wikipedia
“Creodonta
 was coined by Edward Drinker Cope in 1875. Cope included the oxyaenids and the viverravid Didymictis but omitted the hyaenodontids. In 1880. he expanded the term to include MiacidaeArctocyonidaeLeptictidae (now Pseudorhyncocyonidae), OxyaenidaeAmbloctonidae and Mesonychidae. Cope originally placed creodonts within the Insectivora. In 1884, however, he regarded them as a basal group from which both carnivorans and insectivorans arose. Hyaenodontidae was not included among the creodonts until 1909. Over time, various groups were removed, and by 1969 it contained, as it does today, only the oxyaenids and the hyaenodontids.”

Figure 1. Hyaenodon horrid us was the size of a large dog. This carnivorous marsupial was formerly considered a creodont.

Figure 2. Hyaenodon horridus was the size of a large dog. This carnivorous marsupial is considered a traditional creodont.

The LRT recovers
members of the traditional Creodonta in the carnivorous clade of the Marsupialia (Fig. 3). Earlier we looked at similar situation with members of the Didelphidae.

Figure 1. Subset of the LRT focusing on Basal Mammalia including Creodonta.

Figure 3. Subset of the LRT focusing on Basal Mammalia including Creodonta. Members of the Didelphidae and Creodonta are sprinkled throughout this subset.

Here (Fig. 3) the traditional creodont Sinopa (Fig. 4) nests with the extant dasyurids, Dasyurus and Sarcophilus (Fig. 4).

Figure 1. Adding Sinopa to the LRT nests it here, between the extant quoll (Dasyurus) and the extant Tasmanian devil (Sarcophilus).

Figure 4. Adding Sinopa to the LRT nests it here, between the extant quoll (Dasyurus) and the extant Tasmanian devil (Sarcophilus).

References
Andrews CW 1906. Descriptive Catalogue of the Tertiary Vertebrata of the Fayum, British Museum.
Cope ED 1880. On the Genera of the Creodonta. Proceedings of the American Philosophical Society. 19(107): 76–82.
Halliday TJD, Upchurch P and Goswami A 2017. Resolving the relationships of Paleocene placental mammals. Biological Reviews: n/a–n/a. doi:10.1111/brv.12242. ISSN 1464-7931.
Matthew WD 1901. Additional Observations on the Creodonta.  Bulletin of the American Museum 14:1.
McKenna MC 1975. Toward a phylogenetic classification of the Mammalia. Pp. 21–46 in Luckett WP and Szalay FS. Phylogeny of the Primates. New York: Plenum.
Morlo M, Gunnell G and Polly PD 2009. What, if not nothing, is a creodont? Phylogeny and classification of Hyaenodontida and other former creodonts. Journal of Vertebrate Paleontology 29(Supplement 3): 152A.
Polly PD 1994. What, if anything, is a creodont?. Journal of Vertebrate Paleontology. 14: 42A.
Sinclair WJ 1905. The Marsupial Fauna of the Santa Cruz Beds, Proceedings of the American Philosophical Society 49:73.
Wortman JL 1901-1902. Eocene Mammalia in the Peabody Museum, pt. i. Carnivora,” American Journal of Science 11–14.

Encyclopædia_Britannica/Creodonta
wiki/Creodonta

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