Which of the following stomach compartments is absent in pseudoruminants like camels and llamas?

In pseudoruminants like camels and llamas, the omasum is indeed absent. Pseudoruminants have a unique digestive system that is adapted to their specific dietary needs. While true ruminants, such as cows and sheep, have a four-chambered stomach, pseudoruminants possess a three-chambered stomach that includes the reticulum, rumen, and abomasum, with the omasum being excluded from their anatomy.

The omasum has a specific role in the digestion of fibrous plant material by absorbing water and nutrients before the contents move to the abomasum. In contrast, the digestive system of pseudoruminants has evolved to function efficiently with the available resources in their environments, allowing them to extract nutrients without the need for this particular stomach compartment.

Understanding the differences in stomach compartments among various herbivore classifications helps to grasp how these animals adapt to their diets and ecological niches.