Rock hyrax Procavia now a lemur nesting with massive Megaladapis

Did not see this one coming until yesterday.
Now the interrelationship of Procavia and Megaladapis (Fig 1) in the large reptile tree (LRT, 2337 taxa) seems obvious in hind sight. Earlier I did not recognize the notable similarities, especially the homology of those premaxillary and dentary tusks.

Is this a case of phylogenetic miniaturization in Procavia, or island gigantism in Megaladapis? Probably the latter, given the similarity in size of Procavia to the more primitive arboreal primate, Notharctus (Fig 1).

Figure 3. Megaladapis foot compared to that of Procavia, where the medial digit = big toe is gone. ” data-image-caption=”

Figure 1. Megaladapis, an extinct Madagascar lemur, compared to Procavia, the extant rock hyrax, and Notharctus, a North American adapid.

” data-medium-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/08/megaladapis_procavia_588.jpg?w=99″ data-large-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/08/megaladapis_procavia_588.jpg?w=339″ class=”size-full wp-image-94310″ src=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/08/megaladapis_procavia_588.jpg” alt=”Figure 3. Megaladapis foot compared to that of Procavia, where the medial digit = big toe is gone.” width=”584″ height=”1765″ srcset=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/08/megaladapis_procavia_588.jpg?w=584&h=1765 584w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/08/megaladapis_procavia_588.jpg?w=50&h=150 50w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/08/megaladapis_procavia_588.jpg?w=99&h=300 99w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/08/megaladapis_procavia_588.jpg 588w” sizes=”(max-width: 584px) 100vw, 584px” />

Figure 1. Megaladapis, an extinct Madagascar lemur, compared to Procavia, the extant rock hyrax, and Notharctus, a North American adapid.

According to Wikipedia – Hyrax:
“Hyraxes (‘shrew-mouse’) are small, stout, thickset, herbivorous mammals in the family Procaviidae within the order Hyracoidea.”

So, pretty much alone. Now hyraxes nest within Primates in the LRT.

“They are superficially similar to marmots or over-large pikas but are much more closely related to elephants and sirenians.”

In the LRT sirenians are sea beavers. Elephants arise from phenacodonts. So none of these taxa are related to one another. Any similarities (lack of a scrotum, teat location, incisor tusks, flattened nails) are the result of convergence.

Genomics nests all three within Afrotheria, with no transitional taxa proposed given that genomics omits fossil taxa.

“Like most other browsing and grazing animals, they do not use the incisors at the front of the jaw for slicing off leaves and grass; rather, they use the molar teeth at the side of the jaw. The two upper incisors are large and tusk-like, and grow continuously through life, similar to those of rodents. The four lower incisors are deeply grooved “comb teeth.”

Lemurs also have ‘comb teeth’ arising from the anterior dentary.”

“Hyraxes inhabit rocky terrain across sub-Saharan Africa and the Middle East. Their feet have rubbery pads with numerous sweat glands, which may help the animal maintain its grip when quickly moving up steep, rocky surfaces.”

Primates are usually arboreal.

“Hyraxes have stumpy toes with hoof-like nails.”

Primates also have nails (Fig 2). Hyraxes lose the big toe.

“Female hyraxes give birth to up to four young after a gestation period of seven to eight months, depending on the species. The young are weaned at 1–5 months of age, and reach sexual maturity at 16–17 months.”

Similar to primates.

“The smallest of these [hyraxes] were the size of a mouse but others were much larger than any extant relatives. Titanohyrax could reach 600 kg (1,300 lb) or even as much as over 1,300 kg (2,900 lb). Megalohyrax from the upper Eocene-lower Oligocene was as huge as a tapir.”

Those other hyraxes are not yet tested in the LRT.

Figure 3. Megaladapis foot compared to that of Procavia, where the medial digit = big toe is gone. ” data-image-caption=”

Figure 3. Megaladapis foot compared to that of Procavia, where the medial digit = big toe is gone.

” data-medium-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/08/megaladapis.pes588.jpg?w=272″ data-large-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/08/megaladapis.pes588.jpg?w=584″ class=”size-full wp-image-94307″ src=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/08/megaladapis.pes588.jpg” alt=”Figure 3. Megaladapis foot compared to that of Procavia, where the medial digit = big toe is gone.” width=”584″ height=”644″ srcset=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/08/megaladapis.pes588.jpg?w=584&h=644 584w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/08/megaladapis.pes588.jpg?w=136&h=150 136w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/08/megaladapis.pes588.jpg?w=272&h=300 272w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/08/megaladapis.pes588.jpg 588w” sizes=”(max-width: 584px) 100vw, 584px” />

Figure 2. Megaladapis foot compared to that of Procavia, where the medial digit = big toe is gone.

According to Wikipedia – Paenungulata:
“In 1945, George Gaylord Simpson used traditional taxonomic techniques to group these spectacularly diverse mammals in the superorder he named Paenungulata (“almost ungulates”), but there were many loose threads in unravelling their genealogy.[4] For example, hyraxes in his Paenungulata had some characteristics suggesting they might be connected to the Perissodactyla (odd-toed ungulates, such as horses and rhinos). Indeed, early taxonomists placed the Hyracoidea closest to the rhinoceroses because of their dentition.”

So today’s post is a paradigm shift.

Megaladapis fossils are found in Madagascar.
Hyraxes are native to Africa and the Middle East. That makes this an Early Cretaceous radiation, prior to the splitting up of Gondwana.

This appears to be a novel hypothesis of interrelationships.
If not, please provide a citation so I can promote it here.

References
Huxley TH 1869. An Introduction to the Classification of Animals. John Churchill and Sons, London.
Pallas PS 1766. Miscellanea zoologica. AP van Cleef, La Haye, 224 pp.

wiki/Hyrax
wiki/Megaladapis
wiki/Afrotheria
wiki/Paenungulata