Hyracoidea

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The hyracoids (or dassies) are the major group of small-mammal herbivores on the Hajasith, and they are not found on any other continent. Like the rodents of the Kellsith, the hyracoids are well adapted to gnawing on vegetation.

Contents

Overview

  • Class Mammalia
  • Subclass Placentalia
  • Order Hyracoidea

The hyracoid dental formula is 1/2, 0/0, 4/4, 3/3 with a broad diastema behind the incisors. Like rodents, dassies have sharp incisors that grow throughout their lives and no enamel on the posterior surface of their incisors, which makes makes them self-sharpening.

Hyracoids range from the microhyracids, as small as 18 centimeters, to the hypsohyracids, some of which can reach sizes of 1.8 meters. They typically have sharply pointed faces. Hyracoids have tails that are very short, and often non-visible.

Hyracoids have comparativley slow-paced life cycles for small mammals. Life spans are often 7+ years even in the smallest microhyracids, and up to 20 years in the larger hypsohyracids. Gestation periods range from 150-250 days (for comparison rodent gestation periods are rarely over 100 days, and sometimes as low as 25 days).

Like cursorial mammals, hyracoids do not have a clavicle. But most hyracoids have retained the os centrale in their forelimbs, which is absent in cursors. Most hyracoids are agile at jumping and scrambling over uneven surfaces.

Hyracoids are generally social; many species congregate in herds of 50-100. Most species in the order are diurnal.

Families

Image:Hyracoidea_Tree.png

Family Hyracidae

Subfamily Hyracinae (bush dassies)

Subfamily Cremnohyracinae (rock dassies)

Family Dendrohyracidae

The dendrohyracids, or tree dassies, are mid-sized to large dassies adapted for a more arboreal life and are found in many forests and especially open woodland on the Hajasith. Unlike most hyracoids, the dendrohyracids are predominantly nocturnal. They are also more solitary than other families, rarely congregating in groups over 20, and often living singly or in small family groups.

Family Hypsohyracidae

The hypsohyracids are the largest of the dassies, adapted for life on open grassland. They are more specialized for running then other hyracoid families and have lost the centrale, like other running mammals.

Family Microhyracidae

The microhyracids are the smallest of the dassies, but the most numerous and diverse. There is more diversity of activity cycles and feeding style than in the other families.

Family Sulcatahyracidae

The sulcatahyracid family is adapted for more digging than other families. Most species in the family dig out underground burrows, often quite extensive. Sulcatahyracids include species as solitary as the dendrohyracids, living only in small family groups; and also the most social species of any hyracoids: a few sulcatahyracids regularly live in colonies of several hundred.


This article has Design Notes: Hyracoidea/Notes

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