The bearcat Arctictis and the beardog Amphicyon

The latest insight comes from
the just tested and previously overlooked close interrelationship of the extant binturong or ‘bearcat,’ Arctictis now nesting in the LRT (Fig 3) with extinct ‘bear dogs,’ Amphicyon (Fig 1) derived from basal carnivores = civets.

In the primitive African palm civet, Nandinia, the sagittal crest appears at maturity.

Figure 1. Arctictis, Arctodus and two Amphicyon species compared. ” data-image-caption=”

Figure 1. Arctictis, Arctodus and two Amphicyon species compared.

” data-medium-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/08/arctictis-nandinia588.jpg?w=85″ data-large-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/08/arctictis-nandinia588.jpg?w=292″ tabindex=”0″ role=”button” class=”size-full wp-image-88155″ src=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/08/arctictis-nandinia588.jpg” alt=”Figure 1. Arctictis, Arctodus and two Amphicyon species compared.” width=”584″ height=”2051″ />

Figure 1. Arctictis, Arctodus and two Amphicyon species compared to scale alongside more distantly related

Perhaps you’ve heard of bear-dogs.
Perhaps you’ve heard they were all extinct. According to the LRT the extant binturong, Arctictis (Fig 2) is a living beardog…and it looks like one. Like its civet relatives, Arctictis still climbs in trees with ease and is a traditional vivverrid phylogenetically.

According to Wikipedia – Binturong:
“The binturong (Arctictis binturong), also known as the bearcat, is a viverrid native to South and Southeast Asia. The scientific name Arctictis means ‘bear-weasel’.

Figure 1. Arctictis, the extant binturong, is a basal member of the Carnivora. ” data-image-caption=”

Figure 1. Arctictis, the extant binturong, is a basal member of the Carnivora.

” data-medium-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2023/11/arctictis-binturong-lateral-invivo588.jpg?w=300″ data-large-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2023/11/arctictis-binturong-lateral-invivo588.jpg?w=584″ tabindex=”0″ role=”button” class=”size-full wp-image-82026″ src=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2023/11/arctictis-binturong-lateral-invivo588.jpg” alt=”Figure 1. Arctictis, the extant binturong, is a basal member of the Carnivora.” width=”584″ height=”325″ />

Figure 2. Arctictis, the extant binturong, is a basal member of the Carnivora.

Recent corrections to the LRT
have reduced the number of MPTs in the Carnivora subset of the LRT (Fig 3). Earlier iterations nested cats closer to dogs. Now cats nest closer to civets. More bears nest together. Currently the walrus, Odobenus, nests apart from other pinnipeds, closer to otters.

Keep an eye on that one. Remember, it’s a hypothesis = a new idea.

Figure 3. Subset of the LRT focusing on the placental clade, Carnivora. Red taxa are incomplete and have been removed from the LRT. Common names are applied to clades. ” data-image-caption=”

Figure 3. Subset of the LRT focusing on the placental clade, Carnivora. Red taxa are incomplete and have been removed from the LRT. Common names are applied to clades.

” data-medium-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/08/carnivora8-24-lrt588-2.jpg?w=91″ data-large-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/08/carnivora8-24-lrt588-2.jpg?w=309″ tabindex=”0″ role=”button” class=”size-full wp-image-88164″ src=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/08/carnivora8-24-lrt588-2.jpg” alt=”Figure 3. Subset of the LRT focusing on the placental clade, Carnivora. Red taxa are incomplete and have been removed from the LRT. Common names are applied to clades.” width=”584″ height=”1933″ />

Figure 3. Subset of the LRT focusing on the placental clade, Carnivora. Red taxa are incomplete and have been removed from the LRT. Common names are applied to clades.

Amphicyon galushai
(Hunt 2003, Early Miocene, 18mya) is a sister to the extant binturong, Arctictis, in the LRT, both nesting basal to badgers. Hunt wrote, “Here I report the earliest North American occurrences of Amphicyon (18.8–;17.5 Ma),assigning these individuals to a new and previously undescribed species, Amphicyon galushai, from early Hemingfordian sediments of western Nebraska and north-central Colorado. Basicranial, dental, and postcranial anatomy distinguish A. galushai from its contemporary in the Runningwater Formation, the large digitigrade beardog Daphoenodon.”

“The North American species of Amphicyon (A. galushai, A. frendens, A. ingens) most likely adopted ecological roles similar to the large living felids (in particular, the lion Panthera leo). Their robust skeleton with powerful forelimbs, massive clawed feet, heavily muscled jaws with large canines, and a composite crushing/shearing dentition suggest a mobile predator that most likely stalked and ambushed prey from cover, overpowering its victims through sheer size and strength.”

Hunt did not mention Arctictis in the text of his 2003 paper.

The genus Amphicyon is also known from Asia, the homeland of Arctictis.

Though never finished
subsets of the large reptile tree (LRT, 2323 taxa, subset Fig 3) are corrected and improved every day. The clade Carnivora has been fragile, and probably will always be so. Housekeeping continues.

References
Hunt RM Jr 2003. Intercontinental Migration of Large Mammalian Carnivores: Earliest Occurrence of the Old World Beardog Amphicyon (Carnivora, Amphicyonidae) in North America. Bulletin of the American Museum of Natural History 279: 77–115.

wiki/Carnivora
wiki/Arctictis
wiki/Amphicyon