SVP 2018: Pinniped monophyly? Again, no.

Tate-Jones, Hopkins and Davis 2018
discuss current thinking on seal and sea lion interrelations.

Unfortunately
they still hold to the outdated hypothesis of a monophyletic Pinnipedia. Adding more seals and more sea lions won’t help. You have to add taxa that still have paws, like Hyopsodus and Palaeosinopa, as in the large reptile tree (LRT, 1308 taxa; subset Fig. 1).

Figure 1. Subset of the LRT focusing on the Carnivora with tan tones on the bears newly added.

Figure 1. Subset of the LRT focusing on the Carnivora with tan tones on the bears newly added. Desmatophoca nests not with Phoca but with Enaliarctos.

Here’s what they wrote:
“Despite several decades of morphological and molecular study, a consensus on the
phylogeny of the carnivoran suborder Pinnipedia has remained elusive. The majority of
studies within the last 10 years have supported a monophyletic origin for pinnipeds.
Questions remain about whether pinnipeds are more closely related to ursids or
musteloids and about the positioning of early-branching clades, such as
Desmatophocidae.” 

Figure 2. Desmatophoca skull. This extinct sea lion nests with Enaliarctos, not Phoca, the seal.

Figure 2. Desmatophoca skull. This extinct sea lion nests with Enaliarctos, not Phoca, the seal.

Adding Desmatophoca (Fig. 2) to the LRT
nests it not with Phoca, but with Enaliarctos (Fig. 3), not among the seals, but with the sea lions.

The authors report,
“Researchers have alternately placed Desmatophocidae as a sister taxon to phocids (true seals), otariids (sea lions and fur seals), and odobenids (walruses), and no clear consensus yet exists about its positioning.”

Add these taxa,
(Fig. 1) then get back to us.

Figure 6. Enaliarctos nests between Zalophus and Hyopsodus in the LRT.

Figure 3. Enaliarctos nests between Zalophus and Hyopsodus in the LRT.

The LRT is a good fact-checking tool.
Use it to avoid future problems.

References
Tate-Jones K, Hopkins SS and Davis EB 2018. A new Middle Miocene desmatophocid pinniped (Mammalia, Carnivora) from the Oregon coast and its potential for greater resolution of pinniped phylogeny and paleoecology. SVP Abstracts.

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