The genus Lepus, which includes hares, possesses a remarkable dental arrangement that underscores their identity as lagomorphs. Unlike rodents, which have a single pair of continuously growing incisors, Lepus species feature two pairs of incisors in the upper jaw: a prominent pair at the front and a smaller, peg-like pair situated just behind them. This configuration enables efficient processing of tough, fibrous vegetation, a key component of their herbivorous diet.
  • Lepus is a genus of hares within the lagomorph family.
  • Hares have a unique dental formula that includes two pairs of incisors in the upper jaw.
  • The primary incisors are large and chisel-shaped for cutting, while the secondary incisors aid in additional processing.
  • This dental arrangement differs from rodents, which have only one pair of upper incisors.
  • The specialized teeth of Lepus are well-adapted for their herbivorous diet, allowing them to efficiently chew tough plant materials.
*Lepus*
Two pairs

Source Material

Author: Encyclopaedia Britannica

Document: Lagomorph | mammal

Source Material

Author: University of California Museum of Paleontology

Document: Lagomorpha

Differences from Rodents

Comparing Lepus to rodents reveals critical dental distinctions. While rodents possess a single pair of sharp, ever-growing incisors (diastema between incisors and cheek teeth), lagomorphs add a second set of small incisors behind the main ones (double incisor system). Additionally, lagomorphs’ enamel covers both sides of their incisors, enabling more effective wear and self-sharpening, whereas in rodents only the front surface is enamel-coated, promoting a chisel-like function. These traits allow Lepus species to manage abrasive plant diets better than rodents.
  • Rodents have one pair of upper incisors; lagomorphs have two.
  • Lagomorphs have a double incisor system; rodents do not.
  • Lagomorph incisors are enamel-coated on both sides; rodent incisors only on the front.
  • These differences support the lagomorphs’ ability to process tougher, more abrasive vegetation.
Lagomorphs have two pairs of upper incisors
Lagomorphs have enamel on both sides; rodents on the front only

Source Material

Author: USDA Forest Service

Document: Lagomorphs: Rabbits, Hares, and Pikas

Source Material

Author: Encyclopaedia Britannica

Document: Rodent

Ecological Significance of Dental Adaptations

The distinctive dental traits of Lepus species confer significant ecological advantages. Their double incisor system and durable enamel allow them to exploit a wide range of vegetation, including tough, fibrous materials that many other herbivores avoid. This capability helps maintain ecosystem balance by promoting diverse plant consumption and nutrient cycling. Moreover, their teeth’s continuous growth compensates for wear from abrasive diets, supporting their survival in varied and sometimes challenging habitats.
  • The unique teeth enable Lepus to consume a broad spectrum of plant materials, including tough fibers.
  • This dietary flexibility supports ecological balance through varied plant consumption.
  • Continuous tooth growth prevents dental wear, aiding survival in diverse environments.
Ability to consume a wide range of vegetation, including tough plant material
Continuous growth compensates for wear from abrasive diets

Source Material

Author: National Geographic

Document: Lagomorphs: The Unique Teeth of Hares and Rabbits

Source Material

Author: Encyclopaedia Britannica

Document: Lagomorph - Characteristics

Conclusion

The genus Lepus showcases distinctive dental features that set lagomorphs apart from rodents and other mammals. Their two pairs of upper incisors and specialized enamel coatings are key to their success as herbivores in diverse environments.
  • Lepus species have a unique dental formula with double incisors.
  • Their teeth are specially adapted for processing tough, fibrous plant materials.
  • These adaptations provide ecological advantages and support survival in varied habitats.
Two pairs of upper incisors
Enable consumption of diverse, fibrous vegetation