The true meaning of Meriones unguiculatus: The Mongolian Gerbil
Gerbils, jirds and in fact all species on earth are designated a two-part Latin name to identify them. This system of classifying animals is known as 'binomial nomenclature'. These names are useful but also important too because they allow people around the world, no matter what language they speak, to write and communicate to others about any particular species. In theory, every name given is unique to that animal. The scientific name designated to each animal also give clues as to what their relationships are to other animals. The name of each species is given a generic name and also a specific name. The generic name tells us what genus they come from. Some genera only have one species but the vast majority of them have many.
If we take the Mongolian gerbil, or Meriones unguiculatus, we quickly realise that the generic part of its name, Meriones, has been applied to several other Jird species, such as Shaw's jird (Meriones shawi,) Persian jird (Meriones persicus) Libyan jird (Meriones libycus), and so on. The truth of the matter is that our Mongolian gerbil isn't a true gerbil species at all but actually a species of jird, similar in physiology to all the other jirds grouped into this genus. These animals have all been given the same generic name because they all share very similar physical features and adaptations and are much closer related to each other than any other species of rodents.
The generic name is often the first level of taxonomic organisation, simply because all species that are thought to be closely related are placed or grouped together in a genus. If you notice in many examples, these Latin names can often be descriptive of the animal. It is also common for these scientific names to be named after people or often those that discover the animal or even what region it is found in. An example of this is the Shaw's jird or Meriones shawi, and Meriones libycus and Meriones persicus; the Libyan jird and the Persian jird.
In general, this two part naming system is both useful and descriptive but In the case of the genus Meriones this wasn't the case and has led to some considerable confusion. An example of this can be seen with the Mongolian gerbil, or Meriones unguiculatus. We have been taught in many books and on websites that the name roughly translates to "Clawed warrior". While it is true that Meriones was a Greek warrior with teeth on his helmet and was mentioned in Homers Iliad and that 'unguis' is Latin for nail, this wasn't the description of the animal that Johann Karl Wilhelm Illiger was intending to convey when he named the genus Meriones in 1811. This confusion was further compounded In 1900 when Franz Eilhard Schulze introduced another genus group name, Idomeneus, based on the same-named companion of Meriones in the Trojan War. However, If we take a closer look at Illiger's original description, it clearly shows this assumption as being incorrect. Below is an extract from Illiger's book; Prodromus systematis mammalium et avium: additis terminis zoographicis utriusque classis, eorumque (versione germanica) which was published in 1811;
As you can see, rather than Illiger referring to the Greek warrior, in his original description, Meriones derives from μηρος, the Greek word for femur and Illiger accordingly calls the genus "Schenkelthier" in German, which roughly translates as "femur or thigh animal" as does Meriones.
While Illiger used Latin and not English and used "femur" in the description, the German word "Shenkel" is certainly closer to thigh in translation.
So it seems that when naming the genus, Illiger wasn't alluding to their warrior-like fighting skills, but rather their somewhat saltatorial* way of life, for which both their femur and thigh are very well adapted for.
One also has to note of course, that the Mongolian gerbil wasn't part of that original description, so any of that species traits had no influence on the name. However, a much clearer translation of Meriones unguiculatus would be a clawed, femur adapted hopping animal, rather than the clawed warrior translation we currently adhere to.
* Saltatorial:Capable of leaping; formed for leaping; saltatory; as, a saltatorious leg or insect.