Rodents vs Lagomorphs
Though both, rodents and lagomorphs, are mammals that share all the characteristic features of mammals, there is some identifiable differences between rodents and lagomorphs. Before looking into these differences, the most noticeable common feature of these two types of mammals is the continuously growing large chisel-shaped incisors and the distinct diastema between the incisors and the cheek teeth. The presence of these incisors, rodents and lagomorphs have gained the ability of gnawing and hence both these group is collective called ‘gnawing mammals.’ Unlike ungulates, rodents and lagomorphs cannot produce cellulase enzyme, which helps to digest cellulose in plant materials they eat. Instead, they have certain bacterial species in their stomach to do this task.
What are Rodents?
Rodents comprise of the largest and most diversified order of living mammals; Order Rodentia. This Order contains more than 30 families with some 1600 species. Rodents are widespread and found in almost all the continents except Antarctica. The Order includes mice, rats, prairie dogs, squirrels, porcupines, guinea pigs, hamsters. Rodents have ever growing single pair of incisors in each jaw (upper and lower). Their bodies are robust with short limbs and long tails, but there are exceptions.
What are Lagomorphs?
Lagomorphs is a Greek word that has the meaning of “hare-shaped.” Rabbits, hares and pikas are the mammals that resemble this category (Order Lagomorpha). The two families under Order Lagomorpha are, (a) Family Ochotonidae, which includes pikas, and (b) Family Leporidae, which includes hares and rabbits. Lagomorphs are found as native or introduced animals in all the habitats including forests, grasslands, wetlands, deserts, and mountains in all the continents except Antarctica. Rabbits and hares are very much widespread and share more common features including large eyes, long-eares and elongated limbs. Pikas has quite different morphological features from rabbits and hares such as small eyes, round ears and short limbs. All these species are specifically prey species to many kinds of mammals and bird species, but have broad adaptations to avoid their predators.
What is the difference between Rodents and Lagomorphs?
• Lagomorphs include hares, rabbits and pikas, while rodents include mice, rats, prairie dogs, squirrels, porcupines, guinea pigs, hamsters.
• The incisors of lagomorphs are surrounded by a single, unpigmented layer of enamel, whereas rodents have double layered, pigmented layer of enamel which cover only the front part of incisors.
• Lagomorphs have two pairs of upper incisors, whereas rodents have one.
• Unlike most rodents, lagomorphs are strictly herbivorous.
• All the lagomorphs have high-crowned cheek teeth, whereas only some members of rodents share this feature.
• Maxillary fenestrations are present in lagomorphs, whereas they are absent in rodents.
• A baculum (penis bone) is present in rodents, whereas it is absent in lagomorphs.
• Lagomorphs have short tails, whereas many rodents have long tails.