Monodelphis domestica, M sorex and M kunsi split apart

Monodelphis is a small, mouse-like marsupial genus
from South America known from three tested species: M domestica, M sorex and M kunsi (Fig 1). Species within a genus are traditionally supposed to nest together. In the Large Reptile Tree (LRT, 2324 taxa) these three species no longer nest together, but nest at the genesis of two placental clades and one marsupial clade.

Look for three blue stars to find three Monodelphis species in the LRT.

Figure 1. Didelphis, Monodelphis and Chironectes specimens to scale. All are extant, but had their genesis and radiation in the Jurassic. ” data-image-caption=”

Figure 1. Didelphis, Monodelphis and Chironectes specimens to scale. All are extant, but had their genesis and radiation in the Jurassic.

” data-medium-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/09/monodelphis_placentals588.jpg?w=129″ data-large-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/09/monodelphis_placentals588.jpg?w=440″ tabindex=”0″ role=”button” class=”size-full wp-image-88750″ src=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/09/monodelphis_placentals588.jpg” alt=”Figure 1. Didelphis, Monodelphis and Chironectes specimens to scale. All are extant, but had their genesis and radiation in the Jurassic.” width=”584″ height=”1358″ />

Figure 1. Didelphis, Monodelphis and Chironectes specimens to scale. All are extant, but had their genesis and radiation in the Jurassic.

Long-fanged Monodelphis sorex
(Fig 1) still nests with long-fanged Didelphis, the extant Virginia opossum within the Marsupialia.

Long-skulled Monodelphis domestica
(Fig 1) now nests with larger, semi-hooved Alcidedorbignya, basal to ungulates.

Tiny, small-toothed Monodelphis kunsi
(Figs 1, 2) now nests basal to Anagalia (= tenrecs, moles, sengis and walking whales leading to Odontoceti, AND Primates (including bats).

These two large clades can be simplified as early terrestrial placentals and
early arboreal placentals, both starting small.

Figure 2. Monodelphis kunsi now nests basal to primates + bats and Anagale (moes + tenrecs + odontocetes). ” data-image-caption=”

Figure 2. Monodelphis kunsi now nests basal to primates + bats and Anagale (moes + tenrecs + odontocetes).

” data-medium-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/09/monodelphis-kunsi.invivo588.jpg?w=300″ data-large-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/09/monodelphis-kunsi.invivo588.jpg?w=584″ tabindex=”0″ role=”button” class=”size-full wp-image-88753″ src=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/09/monodelphis-kunsi.invivo588.jpg” alt=”Figure 2. Monodelphis kunsi now nests basal to primates + bats and Anagale (moes + tenrecs + odontocetes). ” width=”584″ height=”289″ />

Figure 2. Monodelphis kunsi now nests basal to primates + bats and Anagale (moes + tenrecs + odontocetes).

Work continues.
This is today’s hypothesis. It’s still fragile. That means it may change as further study sheds new light on 622 mammal and pre-mammal taxa, some incomplete.

References
Burnett GT 1830. Illustrations of the Quadrupeda, or Quadrupeds, being the arrangement of the true four-footed Beasts indicated in outline. Quarterly Journal of Science, Literature and Art, July to December, 1829, 336–353.
Carvalho, B de A, et al (5 co-authors) 2011. Phylogenetic relationships and phylogeographic patterns in Monodelphis (Didelphimorphia: Didelphidae). Journal of Mammalogy. 92(1): 121-133.
Kraus DB and Fadem BH 1987. Reproduction, development and physiology of the gray short-tailed opossum (Monodelphis domestica). Lab Anim Sci 37(4):478–482.
Pine RH, Flores DA and Bauer K 2013. The second known specimen of Monodelphs unistriata (Wagner) (Mammalia: Didelphimorphia), with redescription of the species and phylogenetic analysis. Zootaxa3640 (3):425-441.

wiki/Monodelphis
wiki/Monodelphis_kunsi