Poison Came From Sea

The jellyfish’s slimy tentacles were the breeding ground of poison. Later, the potent substance spread to other species.

Animal life began in the sea, and so did poison. Simple worm-like animals and coelenterates like sea anemones and jellyfish have, for more than 500 m years, caught their prey or defended themselves using poison. The first poison-producing organs were probably microscopic structures on jellyfish tentacles. The first venomous land animals were arthropods, such as millipedes and scorpions, which developed 3-400 m years ago. Later, the vertebrates came, and until recently, scientists believed that lizards and snakes were the first ones in this group to brew venom. The discovery of venom glands in the mammal-like reptile E. mirabilis has shown, however, that this ancestor to the mammals was venomous 100 m years earlier. The discovery suggests that many early mammals may also have been venomous.

COELENTERATA

The first poisonous animals were simple organisms, which lived in the sea and consisted of a few types of cells in a jelly-like substance.

MOLLUSCS

Squids were probably the first poisonous mollusc. This group of animals have no spine and mainly live in water.

ARTHROPODS

The group of animals, which carry their skeletons on the outside of their body, was the first one to develop venomous species on land.

VERTEBRATES

Mammals, reptiles and amphibians all have a spine and are thus vertebrates. The proto-mammal E. mirabilis is the oldest one known to have venom.

ECHINODERMS

The small aquatic animals have no head and are often covered with spikes, which may be poisonous. The oldest starfish are 450 m years old.