Aelurodon
| Aelurodon | |
|---|---|
| A. stirtoni skeleton, National Museum of Natural History | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Carnivora |
| Family: | Canidae |
| Subfamily: | †Borophaginae |
| Tribe: | †Borophagini |
| Subtribe: | †Aelurodontina |
| Genus: | †Aelurodon Leidy, 1858 |
| Type species | |
| †Aelurodon ferox | |
| Species[1][2] | |
| |
| Synonyms | |
| |
Aelurodon is an extinct canid genus of the subfamily Borophaginae which lived from the Barstovian land mammal age (16 mya) of the middle Miocene to the late Miocene epoch (5.332 mya).[2][3] Aelurodon existed for approximately 10.7 million years.
Taxonomy
Classification
Aelurodon are a part of a clade of canids loosely known as "bone-crushing" or "hyena-like" dogs, that apparently descended from the earlier genera Protomarctus and Tomarctus.[2] Several species are known from fossils found in the central and western U.S., suggesting a wide geographic range during their peak in the Miocene epoch.[4][2]
Evolution
The earliest occurrence of the genus is A. asthenostylus dating from 16–14 Ma. This species then gives rise to two different anagenetic clades around 15 Ma. One comprises the species A. montaneis, A. mcgrewi and A. stirtoni, going extinct around 12 Ma. The other clade persists until 5.3 Ma and includes A. ferox and A. taxoides. A. taxoides is the most derived and largest species in Aelurodon.[1][2]
The evolution of Aelurodon is characterized by the progressive development of teeth adapted to a more hypercarnivorous diet, a trend consistent with other borophagines.[2]
Description
A. taxoides was the largest species within the genus,[1] Andersson (2005) estimated to have weighed 60 kg (130 lb) on average.[5] Although geographically younger specimens in Nebraska may have shown evidence of a size reduction.[1] A. ferox (the probable ancestor of A. taxoides) was much smaller, weighing 36 kg (79 lb).[5]
Paleobiology
Social behavior
The social behavior of Aelurodon and other borophagines has been debated by experts.[6][5][7][8] Radinsky (1969) noted canids had a larger prorean gyrus than felids. Prorean gyrus is comprised of the prefrontal cortex, and may have been correlated pack social structures as larger canids had a relatively greater amount of prefrontal cortex and have highly developed social behaviors.[8] Radinsky (1973) analyzed the endocast of borophagines and found an unexpanded prorean gyrus, which suggests borophagines didn’t form organized pack structures.[9][6][7]
Munthe (1989) argues that Aelurodon would’ve been solitary, ambush predators because of their more flexible and robust forelimbs. This along with is grasping anterior teeth would’ve enabled it to pull down large prey on their own.[7] Valkenburgh et al. (2003) criticized this argument. They argued while borophagines had more mobility in their forelimbs and forepaws than Caninae, they still lacked the sharp, curved, retractable claws seen in felids, this would’ve made it difficult for borophagines to hold onto large prey. They argued the larger species of Aelurodon (A. ferox and A. taxoides) were social predators due to their hypercarnivory and relative abundance in the fossil record.[6]
However, Andersson (2005) called this argument into question as craniodental and elbow joint morphology of most large borophagines resembled that of pantherinae instead of recent canids. This suggests canines aren’t a suitable analogue for ecological and behaviorally morphology in borophagines. However, the existence of lions shows that carnivorans that can grapple are still capable of adopting pack hunting.[5]
Predatory behavior
The hunting method of Aelurodon has been debated by experts. Muntune (1989) recovered Aelurodon as an ambush predator.[7] However, Van Valkenburgh et al. (2003) suggested their running capabilities are difficult as spotted hyenas are pursuit predators despite limb proportions suggesting otherwise. They suggested that Aelurodon was capable of pursuing prey over a limited distance.[6] Schwab et al. (2019) recovered Aelurodon as a pursuit predators based on the morphology of its bony labyrinth.[10] However, Figueirido et al. (2015) recovered Aelurodon as an ambush predator, although one A. ferox specimen was recovered as a pounce predator. Their analysis also found that pursuit predation among canids emerged during the Pleistocene.[11] Including supplementary materials
Martín-Serra et al. (2016) noted that based on the forelimb morphology, the predatory behavior of the borophagines was not equivalent to any living species as they weren’t as specialized for grappling as ambush predators or as cursorial as pounce-pursuit and pursuit predators.[12]
References
- ^ a b c d Wang, Xiaoming; Richard Tedford; Beryl Taylor (1999-11-17). "Phylogenetic systematics of the Borophaginae" (PDF). Bulletin of the American Museum of Natural History. 243: 1–391. hdl:2246/1588. Archived from the original (PDF) on March 20, 2007. Retrieved 2007-07-08.
- ^ a b c d e f Wang, Xiaoming; Benjamin Wideman; Ralph Nichols; Debra Hanneman (June 2004). "A new species of Aelurodon (Carnivora, Canidae) from the Barstovian of Montana" (PDF). Journal of Vertebrate Paleontology. 24 (2): 445–452. Bibcode:2004JVPal..24..445W. doi:10.1671/2493. S2CID 21694500. Archived from the original (PDF) on December 16, 2008. Retrieved 2015-04-14.
- ^ Aelurodon, Age Range and Collections, PaleoBiology Database yu
- ^ "Vertebrates; Mammalia; Carnivora; Canidae; Aelurodon". Archived from the original on 2011-07-18. Retrieved 2006-04-12. List of Aelurodon specimens from the Berkeley Natural History Museum. (Accessed 4/11/06)
- ^ a b c d Andersson, Ki (2005). "Were there pack-hunting canids in the Tertiary, and how can we know?". Paleobiology. 41 (4): 333–347. Bibcode:2005Pbio...31...56A. doi:10.1666/0094-8373(2005)031<0056:WTPCIT>2.0.CO;2. S2CID 85306826.
- ^ a b c d Van Valkenburgh, B.; Sacco, T.; Wang, X. (2003). "Pack hunting in Miocene borophagine dogs: evidence from craniodental morphology and body size" (PDF). Bulletin of the American Museum of Natural History. 279: 147–162. doi:10.1206/0003-0090(2003)279<0147:C>2.0.CO;2.
- ^ a b c d Munthe (1989). The skeleton of the Borophaginae (Carnivora, Canidae) : morphology and function. University of California Press. ISBN 0-520-09724-6. OCLC 18988571.
- ^ a b Radinsky, Leonardo B. (1969). "Outline of Canid and Felid Brain Evolution". Annals of the New York Academy of Sciences. 167 (1): 277–288. doi:10.1111/j.1749-6632.1969.tb20450.x.
- ^ Radinsky, Leonardo B. (1973). "Evolution of the Canid Brain". Brain Behav Evol. 7 (3): 169–202.
- ^ Schwab, Julia A.; Kriwet, Jürgen; Weber, Gerhard W.; Pfaff, Cathrin (11 January 2019). "Carnivoran hunting style and phylogeny reflected in bony labyrinth morphometry". Scientific Reports. 9 (70) 70. Bibcode:2019NatSR...9...70S. doi:10.1038/s41598-018-37106-4. PMC 6329752. PMID 30635617.
- ^ Figueirido, B.; Martín-Serra, A.; Tseng, Z. J.; Janis, C. M. (2015). "Habitat changes and changing predatory habits in North American fossil canids". Nature Communications. 6 7976. Bibcode:2015NatCo...6.7976F. doi:10.1038/ncomms8976. hdl:10630/32918. PMID 26285033.
- ^ Martín-Serra, Alberto; Figueirido, Borja; Palmqvist, Paul (15 January 2016). "In the Pursuit of the Predatory Behavior of Borophagines (Mammalia, Carnivora, Canidae): Inferences from Forelimb Morphology". Journal of Mammalian Evolution. 23 (3): 237–249. doi:10.1007/s10914-016-9321-5. hdl:10630/32922.
Further reading
- Xiaoming Wang, Richard H. Tedford, Mauricio Antón, Dogs: Their Fossil Relatives and Evolutionary History, New York : Columbia University Press, 2008; ISBN 978-0-231-13528-3