Eupleres joins Paroodectes at the base of the Placentalia in the LRT

A living genus,
Eupleres (Fig 1), is a late survivor (on Madagascar, of course) of the Late Jurassic appearance of the clade Placentalia in the large reptile tree (LRT, 2324 taxa).

This nesting is a result of recent housekeeping = trying to understand hypothetical interrelationships. This new nesting supersedes earlier attempts.

Figure 1. The pecursors of the last common ancestors of all placentals in the LRT: Eupleres and Paroodectes. ” data-image-caption=”

Figure 1. The pecursors of the last common ancestors of all placentals in the LRT: Eupleres and Paroodectes.

” data-medium-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/08/pre-placental-transition_eupleres588.jpg?w=102″ data-large-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/08/pre-placental-transition_eupleres588.jpg?w=349″ tabindex=”0″ role=”button” class=”size-full wp-image-88269″ src=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/08/pre-placental-transition_eupleres588.jpg” alt=”Figure 1. The pecursors of the last common ancestors of all placentals in the LRT: Eupleres and Paroodectes.” width=”584″ height=”1713″ />

Figure 1. The pecursors of the last common ancestors of all placentals in the LRT: Eupleres and Paroodectes.

There is no phylogenetic miniaturization
at the last common ancestor node of all placentals in the LRT. Eupleres and Paroodectes are not tiny taxa. They were both likely smaller than extant mice in the Middle to Late Jurassic, and arboreal.

The loss of the marsupium (= pouch) in Monodelphis
preceded the Early Cretaceous appearance of little, but vicious, Vincelestes.

The burning question is:
Was Monodelphis unique (a one shot wonder) in having one vagina and no pouch? Or was that the morphology of the intervening taxa leading to Eupleres? Or did the Monodelphis morphology develop during the Cenozoic?

Eupleres young are able to travel through the jungle with their mother within two days.

Figure 3. Thylacinus, the Tasmanian wolf, had typical maruspial reproductive organs and a pouch. ” data-image-caption=”

Figure 3. Thylacinus, the Tasmanian wolf, had typical maruspial reproductive organs and a pouch.

” data-medium-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/08/thylacinus_invivo.jpg?w=300″ data-large-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/08/thylacinus_invivo.jpg?w=584″ tabindex=”0″ role=”button” class=”size-full wp-image-88271″ src=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/08/thylacinus_invivo.jpg” alt=”Figure 3. Thylacinus, the Tasmanian wolf, had typical maruspial reproductive organs and a pouch.” width=”584″ height=”390″ />

Figure 3. Thylacinus, the Tasmanian wolf, had typical maruspial reproductive organs and a pouch.

The LRT helps resolve this problem.
Descendants of Vinceletes include several marsupial carnivores, including Sarcophilus (the Tasmanian devil) and Thylacinus (the Tasmanian wolf, Fig 3), both of which have typical marsupial organs and pouches.

According to Wikipedia – Placentalia
“True placentals may have originated in the Late Cretaceous around 90 mya, but the earliest undisputed fossils are from the early Paleocene, 66 mya, following the Cretaceous–Paleogene extinction event.”

This mistaken chronology follows the splitting of Madagascar from other continental masses, when it should have preceded that split in order for Eupleres (Fig 1) to end up on that island and there alone. Plant rafts are the alternate hypothesis.

The authors of this Wikipedia page give several paragraphs to placental genomics, which recovers untenable clades like Afrotheria and Laurasiatheria.

Deep time genomics is a problem for paleontology in general.
Someone from academia needs to point the finger at this issue. As irate readers of this blogpost often note, academics don’t listen to amateurs.

Eupleres major
(Doyère 1835 snout-rump length up to 65cm + 25cm tail) is the extant (but nearing extinction) Western falanouc, a purported mongoose from Madagascar. Here it nests as a basal-most placental alongside Paroodectes. Note the elongate premaxilla, the gracile mandible, the reduced canine and other traits common to both. Diet of worms, slugs, snails. A single young is born in a burrow and can travel with the mother within two days. Madagascar separated from other continental masses in the Late Jurassic 155 mya.

References
Doyére LMF 1835.Notice sur un mammifére de Madagascar, formant le type d’un nouveau genre de la famille des Carnassiers insectivores de M. Cuvier. Ann. Sci. Nat. Zool. 4: 270–283.

wiki/Placentalia
wiki/Eupleres