Arboreal locomotion a synapsid of the late Permian, about 260 million years ago. Some animals are exclusively arboreal in habitat, such as the tree snail. Arboreal habitats pose numerous mechanical challenges to animals moving in them, which have been solved in diverse ways. These challenges include moving on narrow branches, moving up and down inclines, balancing, crossing gaps, and dealing with obstructions. Moving along a narrow surface poses special difficulties to animals. During locomotion on the ground, the location of the center of mass may swing from side to side, but during arboreal locomotion, this would result in the center of mass
Photosensitivity in animals Photosensitivity in animals Photosensitivity is an abnormal skin reaction to direct sunlight exposure. It is unrelated to a sunburn. These reactions are due to photosensitization, the accumulation of photosensitive compounds beneath the skin. In some cases, the photodynamic substances come from ingested plants or drugs, after being metabolized or not. In other cases, the photodynamic substances may be produced in the body itself due to inborn errors in pigment metabolism, especially those involving the heme synthesis. Photosensitivity reactions are usually seen in herbivorous or omnivorous animals, though such reactions are not uncommon among carnivores. Photosensitivity reactions are characterized by severe