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| Eurotamandua |
While the name translates as "hyena-tooth" due to the description of the first fossils to be found, hyaenodonts were not hyenas, or even closely related to them. They belonged to a group entirely separate from the living carnivorans, and that survived alongside them until as recently as 10 million years ago, near the end of the Miocene. For most of that time, they could be regarded as primitive holdovers, vestiges of their past glory, but in the Eocene they were still at the height of their power.
Having said this, the first hynaenodonts to enter Europe were physically unimpressive, succeeding largely due to the fact that there wasn't much else to compete with. These are traditionally grouped into a subfamily called the "proviverrines", although the details are debated. For one thing, it's not at all clear which family (if any) they are a subfamily of. This is largely due to the higher-level classification having shifted since they were first named, but the membership of the group is also in doubt, since it's not at all clear that all of the traditionally defined species share a unique common ancestor with one another.
One animal that we definitely can say is proviverrine is Proviverra itself. This was about the size of a small stoat, at around 20 cm (8 inches) in length. While they had longer legs, if not particularly suited for fast running, they probably ate much the same diet as stoats, too, feeding on small mammals and birds, and likely some insects. While its teeth were only just developing the meat-cutting blades that would later become common in hyaenodonts, analysis of the inside of the skull suggests a brain that was relatively large for its size, comparing favourably with many modern carnivores.
While the proviverrines are usually regarded as being unique to Europe, they prospered there, with several different species having been described. As time went on, they became larger and more specialised. Arfia, for example, although now often placed in a separate subfamily, was about the size of a fox, and had limbs adapted for chasing down prey, albeit with enough flexibility that it may have been able to climb trees if it wanted to. On the other hand, Lesmesodon, one of the smaller species at no more than 400g (14 oz.), had teeth that seem particularly well suited to eating insects, while Eurotherium, weighing in at up to 5 kg (11 lb.), would likely have eaten much more meat and may well have been a scavenger.
If they are separate groups, one theory holds that proviverrines proper originated in Africa, while animals such as Arfia came across from North America. They would have done so, not by crossing a land bridge across the Bering Strait, as was more common in later geological times, but across the North Atlantic. This is because the most northerly reaches of the Atlantic Ocean were closed off at times, making it possible to walk from Canada, via Greenland, to Norway and Scotland.
It is possible that Hyaenodon itself, which first appeared in Europe during the Middle Eocene around 41 million years ago, followed this route, since it originated in North America much earlier... but it is perhaps more likely that it came the long way around, through Asia. Although better known from its larger, American forms, the European ones were relatively small, with some estimated as weighing just 2 kg (4½ lbs.), smaller than most domestic cats.
This is not to say that larger mammalian carnivores did not inhabit Europe, at least by the Middle Eocene. These belonged to a group of hyaenodonts named the hyainailiourines, which may have originated in either Asia or Africa.
Pterodon was only the second hyaenodont of any kind to be described, back in 1839. Although that early description includes some limb bones, they have since been lost, and it isn't clear that they really belonged to the same animal, so all we have for certain is the skull. Based on this, it has been estimated it may have weighed around 30 kg (66 lbs.), similar to a retriever or English setter. Inevitably, however, there is a lot of uncertainty in that, given that we don't know the exact shape of its body. However, since we do have the teeth, it was clearly a flesh-eater and may have had some limited ability to crack bone.
The largest known mammalian carnivore in Eocene Europe was Kerberos, named for the three-headed dog guarding the Greek underworld. First described in 2015, the only known fossil came from the Tarn region of southern France. That study estimated the animal to have weighed up to 140 kg (310 lbs.) in life, similar to an adult lioness. Because, unlike Pterodon, we do have one of its legs, we can say that it had flat feet, similar to those of a bear, and so would have walked along the ground. The general shape, however, suggests that it would not have been a pursuit predator, and probably wasn't very good at climbing, either. It was clearly highly carnivorous, and would have scavenged on carrion when it was available, with the teeth and jaw muscles likely strong enough to crack bone, but not ideally suited to doing so.
It wasn't quite the top predator of its day, since Europe, like many parts of the Eocene world, was also home to gigantic crocodiles, but it must have been close.
During the Early Eocene, however, before Kerberos lived, it's unlikely that the largest mammalian carnivore would have been a proviverrine, or even a hyaenodont. At least two groups of relatively large carnivorous mammals did exist, although each was represented by relatively few species. Palaeonictis somewhat resembled a wolverine in borth size and shape, and is better known from North America, where even larger forms lived. Given the heavy build that this implies, it probably wasn't a fast runner, although some of its features suggest that it may have been able to climb trees. It was an oxyaenid, a primarily American group related to, but distinct from the hyaenodonts. They died out in Europe at the end of the Early Eocene, perhaps only living there for a few million years.
The mesonychids were less closely related to the creodonts, being thought to be closer to the hoofed mammals. Despite this, they were carnivorous, and while they, too, were predominantly American, they briefly entered Europe in the Early Eocene. Two examples are known; Pachyaena, a roughly wolf-sized animal living on the northern islands of the archipelago, and the badger-sized Hyaenodictis in the south. The latter lasted longer, dying out 48 million years ago, as the Middle Eocene dawned, although whether it was out-competed by the proviverrines or became extinct for some other reason is not obvious.
There were probably no true carnivorans in Eocene Europe, in the sense of anything descended from the last common ancestor of the living forms. However, a broader definition could include anything closer to the carnivorans than to the hyaenodonts and oxyaenids and there were some animals on the continent at the time that fit that description at least.
Perhaps the closest such animal in Europe to the living forms was Quercygale. This was first described from the Quercy Phosphorites, a major Cenozoic fossil formation in southern France, but is also known from Germany, Switzerland, Spain, and the Isle of Wight in England. It was about the size of a house cat, although with some variation among the individual species, and, if it was anything like some of its other relatives, was probably arboreal. It was also unusually successful, surviving for almost the entire length of the Eocene - hardly a short span of time. Analysis of the inside of the skull suggests a brain smaller than would be expected of a modern carnivoran of the same size, with less developed cerebral cortices, but not necessarily by much.
Other carnivorous mammals were even less related to the modern animals than were the hyaenodonts. Anatoliadelphys is an extreme example, a metatherian carnivore that survived into the Middle Eocene in Turkey (then the easternmost major island of the European archipelago). Related to today's marsupials rather than to placental mammals, it must have been a late survivor of some ancient lineage that we otherwise know little of. It had strong jaws and large teeth suited for biting down on hard objects, and was likely adept at clambering about in the trees, using what appears to have been a prehensile tail for support.
If the mesonychians were related to the herbivorous hoofed mammals, but were themselves carnivorous, the opposite seems to have been true of the pantolestans. They, so far as we can tell, belong to the same section of the mammalian family tree as the carnivorans, but their teeth suggest that they ate plants. Europe was home to one particular family within this group, the paroxyclaenids, which were tree-dwelling fruit-eaters. While most, such as Merialus and Paraspaniella, were much smaller, the largest, Welcommoides, reached 4 kg (9 lbs.), the size of a large cat, and successfully crossed the water to Asia, reaching as far as Pakistan. Most died out around 48 million years ago, at the end of the Early Eocene, but a few managed to survive for a further 10 million years, perhaps eventually wiped out by the unusual heat of the Eocene Climatic Optimum at around that time.
However, one other group of carnivoran relatives was much luckier. They may have diverged from the common ancestor of carnivorans, hyaenodonts, oxyaenids, and all those difficult-to-classify "stem" carnivoramorphs such as Quercygale, at about the same time as the pantolestans did. Which is to say, very early on, perhaps around the time of the extinction of the non-avian dinosaurs. But not only did they survive into the Eocene, they are still alive today.
These are the pangolins. The oldest known pangolin is Eomanis, which is known from Germany, very far from where pangolins live today. It was remarkably similar to the modern animals in size and shape, and, while the details of anatomy diverge just enough to place it in a different family than that we have today, they are close enough that it is difficult to see what else it might be. The well-preserved fossils reveal that the scales did not extend onto the tail, and that it still ate some fruit, which the modern species generally do not.
If that was a surprising animal to find in Germany, Eurotamandua was even more so. When it was discovered in 1981, it gave every impression of being an anteater, and was classified as such. In retrospect, this made no sense, as anteaters are unique to South America, and it's very difficult to see how any could have reached Germany from there. Later examination of the skeleton determined that it lacked many of the defining features of true anteaters, and it was instead placed with the pangolins.
Nonetheless, the well-preserved fossil indicated that it was not scaled, but was instead furry, as we would expect an anteater to be. The assumption at the time was that it represented an early branch that had split off before the scales had developed. A new analysis, conducted in 2023 but only formally published in May of this year, places it a little further away - closer to pangolins than to anything else alive today, but outside even the order, let alone the family, of the modern species.
[Photo from Rose et al. 2026, available under CC-BY-4.0.]
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