Astrapotheres are now basal elephants in the LRT

Astrapotherium magnum
(Burmeister 1879, Hatcher 1901; Paleocene-Miocene, 59-12 mya; 3m long) was considered a South American ungulate and a member of the order, Astrapotheria, by the authors of Wikipedia. They reported, “The history of this order is enigmatic.”

Here
Astrapotherium nests between Anthracobune + Cambaytherium and Numidotherium + Gomphotherium + other elephants.

Click the links to see the updated images.

Like an elephant,
Astrapotherium had large and ever-growing curved incisors (not canines as mistakenly identified earlier). Apparently they scraped against the lower canines during life producing sharp tips. The rostrum was much shorter than the mandibles as in shovel-tusk elephants. The fingers and toes were small and apparently elevated by pads, as in elephants. The narial opening was elevated to the top of the skull to facilitate a trunk.

Astraponotus assymemetrum (Ameghino 1901; Late Eocene 35mya) is a South American taxon nesting with Astropotherium.

On the dentary = mandible
Astrapotherium has canines + smaller incisors. Transitional Numidotherium has larger incisors than canines. Gomphotherium loses the canines on the elongated dentary with longer incisors.

That rare posterior extension of the palatine extends to giant Megistotherium

Megistotherium has been difficult to understand.
Now (hopefully at long last), the posterior extension of the palatine in this taxon is linking this giant member of the Carnivora with a much smaller, primitive, extant taxon, Nasua,the coatimundi, which also shares this rare trait with the raccoon, Procyon, and the binturong, Arctictis.

Click links to see images at ReptileEvolution.com.

Megistotherium osteothlastes
(Savage 1973; Miocene, 23mya; 66cm skull length) was originally considered a giant hyaenodontid creodont. After rescoring this taxon, here it nests with the much smaller, extant coatimundi, Nasua. The jaw muscles were enormous filling the high cranial crest. The large diameter canines were housed in large, laterally expanded maxillae. The brain case was narrow. The fragile postfrontals appear to have broken off. The premaxillae each include room for only one tiny tooth, if not absent altogether. A key trait is the posterior extension of the palatine far beyond the tooth row, a trait common to this clade. The fragile otic bulla = ectotympanic is missing here, perhaps via taphonomy, so was scored with a ‘?’ rather than ‘bulla absent’.

These are choices one makes when scoring taxa, taking into consideration overall  shape AND details. Feel free to argue for another nesting. Bring evidence when you do.

The great size of Megistotherium vs the much smaller size of Nasua
– and the changes that inevitably happen with Cope’s Rule – seem to be the reason why these two taxa have remained phylogenetically separated until now.

According to wiiki/Megistotherium
“Due to the paucity of material assigned to Megistotherium, size estimates for the genus have varied considerably over the years. The validity of Megistotherium has been questioned by several authors, who suggest that it is actually a junior synonym of Hyainailouros. The matter is complicated by the paucity of dentition in Megistotherium.”

No other taxa close to Hyainailouros have been tested by the LRT. The tooth roots are visible in the Megistotherium data, but the tooth crowns are missing.

Updates have been made to the LRT and the Megistotherium page.

References
Savage RJ 1973. Megistotherium, gigantic hyaenodont from Miocene of Gebel Zelten, Libya. Bulletin of the British Museum (Natural History) Geology 22(7):483–511.

wiiki/Megistotherium

pterosaurheresies.wordpress.com/2026/03/04/posterior-palate-extensions-in-the-raccoon-family/

New Homo naledi YouTube video with clickbait title

A new Michael Button video
entitled ‘We Found a Human Species That Shouldn’t Exist.’
youtube.com/watch?v=Jd9iuhux_f0

Then, maybe it’s not human. Maybe convergent with Homo.

Here’s my comment:
Actually a very simple answer: Homo naledi is related to Australopithecus (both have that dished face in profile and other traits), which was a chimp, bipedal by convergence. So it should not be named ‘Homo’ naledi, but ‘Australopithecus’ naledi.

Human ancestors were in the gibbon lineage: Sahelanthropus, Hylobates, Ardipithecus,  Oreopithecus and the Homo floresiensis relatives. Gibbons are bipedal. Have a long Achilles tendon. Hide fertility signals. Born naked. Hair: blonde, brown, black and red.

There’s more of a brand name in ‘Homo‘, just like ‘Tyrannosaurus‘ and ‘Archaeopteryx‘.

Still a great find. Congrats are in order.

References
wiki/Homo_naledi

Posterior palate extensions in the raccoon family

In most mammal palates,
the palate = palatine extends no further than the posterior molar.

In Procyon, the raccoon,
Nasua, the coatimundi and in Arctictis, the binturong, the palatine extends posteriorly far beyond the tooth row. Prionodon, the banded linsang is also on this list.

Click on the links to see the images at ReptileEvolution.com.

I emailed two professors,
Larry Witmer (Ohio U) and Christopher Brochu (Iowa College of Liberal Arts and Sciences), asking ‘what is the term for such an extension?’ and ‘what are the ramifications?’ = uses for such a palate extension. Both replied the same: ‘there is no term for this‘.

So I ask you, dear readers,
what does the literature report (if anything) about these palate extensions.

If nothing, what are your thoughts?

Premolar evolution in Tenrec though Tursiops

Curious about those atypically monomorphic odontocete teeth
I added DGS colors to two odontocetes and several ancestors back to Tenrec. I was seeking dental patterns in their evolution from a basal mammal tooth morphology and tooth count (= incisors, canine, premolars and molars) to a derived supernumerary all-canine-like appearance.

Hyperdontia  can occur in humans, too.

Here’s the hypothetical evolution of odontocete premolars (not to scale).
Starting with three premolars in Tenrec, then four, four, seven, eight and finally 17 in Tursiops. In each case 4 molars were retained. These premolars and molars all became canine-like in shape with a single root, not double-rooted (as in typical premolars) and not triple-rooted (as in typical molars).

‘Canine-like’ is ironic because
odontocetes and their ancestors lacked even one canine in the maxilla to start with. Much earlier the upper canine was phylogenetically lost following the marsupial Asioryctes in this placental 2 clade that included other canine-less members, including of xenarthrans and sengis.

Arrows in the diagram
point to the migrating narial openings in these odontocete ancestors.

Click this link and scroll down  to view the chart of odontocete skulls.

This is a hypothesis of tooth evolution in odontocetes
and their ancestors. The changes here can only be seen by comparative anatomy, not in individual skulls. Competing hypotheses are welcome if they include the same taxon list.

In this case, tooth position is more important than tooth shape.
In other cases, tooth shape is more important in tooth identity.
In still other cases, it’s a mixture of the two: with premolar-like molars, molar-like premolars and canine-like premolars following vestigial canines.

This account of tooth number, shape and position
is only one reason why mammals continue to be difficult to score in phylogenetic analysis.

Odontocetes break the rules.

By convergence
The Early Jurassic symmetrodont, Feredocodon, had 0 canines and 6 premolars (with two roots), but it also had 5 incisors (with semi-split roots) and 5 molars (with 3 roots).

Final note
Killer whales are not giant dolphins.

Rather, dolphins are miniaturized killer whales – with about twice as many premolars.

References
reptileevolution.com/orcinus.htm

https://pterosaurheresies.wordpress.com/2025/05/05/more-traditional-canine-teeth-reidentified-as-premolars-now-in-odontocete-ancestors/

https://pterosaurheresies.wordpress.com/2020/06/24/reversals-produce-whale-teeth-part-2/

https://pterosaurheresies.wordpress.com/2019/01/02/mammal-tooth-evolution-toward-complexity-and-then-simplicity/

The ‘truth’ of Manatee evolution YouTube video

New manatee YouTube video by Ben G Thomas
provides the traditional view of manatee origins, recently shown to be invalid by the large reptile tree.

youtube.com/watch?v=OnT7_wyMuRM

My ccmments follow
Correction – manatees and sea cows arise from Moeritherium, then Castoroides (which fed on underwater grasses), then Castor, the beaver. These are all rodents NOT related to hyraxes (= notoungulates) and NOT related to elephants (= phenacodontids). Unrelated desmostylians arose from hippos and gave rise to mysticetes in trait analysis. Thus the changes are NOT dramatic, but gradual. Beavers and manatees share the same tail shape. This is why deep time genomic tests cannot be trusted because they recover false positives too often. Sorry. You’ve been led astray by out-of-date college textbooks. See ‘the large reptile tree’ online. It tests all competing taxa.

More here from 2024.

Phylogenetically miniaturized Vulpavus gives us Hyopsodus

According to wiki/Hyopsodus:
“Hyopsodus is a genus of extinct early ungulate mammal of the family Hyopsodontidae, a group associated with or basal to the Perissodactyla. It was a small mammal with skull of about 6 cm in length. Fossils of this genus have been found in the Eocene of North America, especially the Bighorn Basin region of the United States. It has also been found in Eurasia.”

Here in the LRT
Late Eocene Hyopsodus is a primitive placental 1 taxon close to Early to Middle Eocene Vulpavus, but phylogenetically miniaturized in several aspects, coming to resemble a hypothetical juvenile Vulpavus following mammalian ontogeny patterns.

Prior studies overlooked this hypothetical interrelationship.
See: reptileevolution.com/vulpavus_ovatus for images.

Phylogenetic miniaturization
Hyopsodus was smaller overall, had relatively larger eyes, smaller canines, shorter legs and a shorter tail, altogether resembling a hypothetical ‘puppy’ of Vulpavus.

References
Cope ED 1881. The Condylarthra (Continued). American Naturalist 84;18: 892–906.
Cope ED 1881. Mammalia of the lower Eocene beds. American Naturalist 15:337-338.
Leidy J 1870. Remarks on a collection of fossils from the western territories. Proceedings of the Academy of Natural Sciences of Philadelphia 22: 109–110.
Matthew WD 1909. VI. The Carnivora and Insectivora of the Bridger Basin, Middle Eocene. Memoirs of the American Museum of Natural History. 9(6):576pp.

wiki/Hyopsodus
wiki/Vulpavus