Some Notes On Fox Ancestors

 

Ancient Fossil of Arctic Fox Discovered in Tibet (Representational Image) Wikimedia Commons/Billy Hathorn]

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The vulpes riffautae (Vulpes riffautae) is a species of fox that became extinct in the late Miocene of Chad (about 70 years ago). Fossils of V. riffautae may represent the earliest record of Old World canine canidae. V. riffautae was intermediate in size between the Ruppel fox (Vulpes rueppellii) and the Fennec fox (V. zerda). The mandible is narrow and shallow. Just before the dorsal root of p2 the join ends. The masseter fossa is quite deep. The small posterior mental foramen is located below the dorsal root of p3, and the large anterior mental foramen lies between the root of p1 and the ventral root of p2.

As cousins to wolves and dogs, foxes are a great model for dog domestication. They diverged from the wolf lineage about 12 million years ago (a brief time period, evolutionarily).

The first specific fossils of foxes appear during the Pliocene era, about 5 million years ago. While some larger canidae species died out due to a loss of large prey (like the woolly mammoth or giant sloth), foxes survived because they preyed on much smaller animals and could survive the loss of big herbivores.

Foxes were present in Britain before the last ice age and seem to have recolonised on their own about 10,000 years ago – well before even the Romans set foot on our shores.

Regarding foxes the question one might ask is whether ancient foxes were more carnivorous than today's ?  A technical paper titled Were ancient foxes far more carnivorous than recent ones?—Carnassial morphological evidence by Elwira Szuma of the  (Polish Academy of Sciences) and Mietje Germonpré, of the Royal Belgian Institute of Natural Sciences and edited by Cyril Charles published by the National Library of Medicine in 2020 looks at this question https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6953794/

The conclusions:

"Morphotype analysis of the lower carnassials in ancient and extant populations of the arctic and red fox revealed distinctive evolutionary trends in the two species. In the arctic fox the progressive changes in dental form tended towards hypercarnivory, whereas in the red fox the most primitive characters have been retained from the Pleistocene to recent times. Such evolutionary tendencies for both foxes are a result of their varying life strategies and evolutionary trajectories in the Late Pleistocene, and Holocene. The arctic fox occupies the most extreme habitats of the northern hemisphere, and over the last decades its range has been declining in response to pressure from the red fox." 

 

Geographic distribution of the recent and fossil samples of the arctic Vulpes lagopus and red foxes Vulpes vulpes used in the study. Black rhomb-recent populations of the arctic fox measured by Szuma (2011), empty rhombfossil populations of the arctic fox measured by Szuma for the study, grey circle-recent populations of the red fox measured by Szuma (2011); empty circle-fossil population of the red fox measured by Szuma for the study. Information about the samples can be found in Table 1. https://doi.org/10.1371/journal.pone.0227001.g001

Now, that thorny question about Vulpes ancestors. Well a summary of Saverio Bartolini Lucenti on the Università degli Studi di Firenze - UniFI web page seems to suggest that he has found the answer https://www.unifi.it/art-4755-the-ancestor-of-the-european-fox-has-only-one-name.html?newlang=eng

"The evolutionary history of modern fauna can be very difficult to reconstruct when the finds are scarce and difficult to interpret, as in the case of the European red fox.

"The study signed by Saverio Bartolini Lucenti, research fellow of the Department of Earth Sciences, has bridged this limit and has put in order the attribution of fossil records available to the scientific community showing that, contrary to what paleontologists believed, during the Lower Pleistocene lived in Europe only one species of fox, called Vulpes alopecoides. The discovery, made also thanks to fossils housed in the Mueum of Geology and Paleontology of the University Museum System, was published in Quaternary Science Reviews.

“Over the last 100 years, three different species of foxes have been featured in the European fossil record. The first, Vulpes alopecoides, was defined for the first time in 1913 by Domenico Del Campana, thanks to a fossil from the Upper Valdarno dated to 1.8 million years ago, preserved in the collections of the University Museum System. This species must have been a little smaller than the extant red fox and was considered by paleontologists to be one of its ancestors. Based on findings from Hungary, two additional species were defined in the 1930s, Vulpes praeglacialis and Vulpes praecorsac, which allegedly populated our continent between 1.5 million and 800 thousand years ago,” says Bartolini Lucenti

"This interpretation was based on a fossil record characterized by numerous gaps and rather incomplete remains that have made it difficult so far to reconstruct the possible affinities and relationships between the three distinct species.

“To clarify the matter, together with a colleague of the Institut Català de Paleontologia in Barcelona, I conducted the morphological and biometric analysis on the type materials, that is, the reference samples for the description of the three species among which the Florentine specimen (in the second photo of the gallery) and a large fossil specimen of European foxes dating back to a period ranging from 3 million to 800 thousand years ago. We discovered that the variability between the fossil samples, attributed to three different species, is actually less than that found between individuals of the extant red fox,” explains Bartolini Lucenti.

“Our analysis, which made use, among other things, of the comparative study of 45 European red fox individuals housed at the La Specola Zoology section allows us to realistically state that during the Lower Pleistocene in Europe there lived only Vulpes alopecoides, the most plausible ancestor of the foxes that populate our continent,” 

Artistic reconstruction of Vulpes alopecoides (c)2023 Prehistoric Fauna: though such things are prone to human bias and limitation of knowledge of the actual animal. Here the artist on Prehistoric Fauna wiki has based the appearance on what would pass for a modern fox though we know the Old British and W. European foxes were overall brown in colour without the white or black. https://prehistoric-fauna.com/Vulpes-alopecoides