Rattus rattus (1) Black Rat Mouse Skull Mammalia Rodentia Muridae

Black Rat Skull Mouse Rattus rattus cm 3.3 Mammalia Rodentia Muridae, complete of mandible, only a piece, as in photos.
Family: Muridae.
Common name: Roof Rat, Ship Rat, House Rat, Alexandrine Rat, Old English Rat.
Syn. Mus rattus.

The Black Rat (Rattus rattus Linnaeus, 1758) is a rodent mammal belonging to the Muridae family. It is included in the list of the 100 most harmful invasive species in the world. It measures from 30 to 40 cm, tail included, with a weight of up to 300 g. Black rats live in large groups among which there is a rigid hierarchy. During the day they tend to rest in nests built with grass stems and leaves, generally located high up, for example among the branches of a tree or on the upper floors of a building (particularly in attics, hence the common name of " roof rat"): they only rarely dig underground burrows. Up to five litters can breed throughout the year. To move at great heights, the black rat uses its long tail as a counterweight during its movements, to maintain balance and avoid falling.
Unlike sewer rats, the black rat is purely herbivorous: it feeds mainly on cereals, fruit and grains, preying on silos in rural and port areas and causing even considerable damage, as it contaminates the food with urine and excrement, making itself thus a vehicle for numerous diseases such as leptospirosis. If necessary, the black rat does not mind feeding on insects or other invertebrates, eating anything it can digest if necessary.
The species, most likely originating from Asia, spread following Arab traders, reached Europe with ships returning from the Holy Land during the Crusades, and gradually spread throughout the world.
It is believed that the arrival of the black rat in Europe preceded that of the gray rat by six centuries: it coincided with the outbreak of the bubonic plague epidemic that devastated the continent, caused by bacteria carried by fleas belonging to the Xenopsylla cheopis species, which thrives in the fur of these animals. The gray rat, more aggressive and adaptable, has replaced the black rat over time in most of the temperate and cold areas of its range, while in tropical areas it is the black rat that has the upper hand in the competition. In fact, it seems that the black rat can also tolerate both warmer and colder climates than the gray rat.
Three subspecies have been recognized: Rattus rattus alexandrinus, Rattus rattus frugivorus and Rattus rattus rattus.
Skull: compared to the Brown Rat, it presents significant differences at the cranial level, in particular the black rat does not have the two lateral bony crests typical of the gray rat, while the skull is narrower and more elongated, with larger eye sockets and molars of different shape.