''Megadictyon'' is a genus of

Cambrian The Cambrian Period ( ; sometimes symbolized Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million years ag ...

lobopodian The lobopodians, members of the informal group Lobopodia (from the Greek, meaning "blunt feet"), or the formally erected phylum Lobopoda Cavalier-Smith (1998), are panarthropods with stubby legs called lobopods, a term which may also be used as ...

with similarities to ''

Jianshanopodia ''Jianshanopodia decora'' is a Cambrian lobopodian. Its frontal, grasping appendages bear wedge-shaped plates. Its limbs branch, instead of being tipped with claws as many lobopods' are. It has a sediment-filled gut surrounded by serially repe ...

'' and ''

Siberion ''Siberion'' is an extinct genus of lobopodian from the Sinsk biota of Russia. Its anatomy, including the proboscis-like organ projecting from the face and prominent grasping first pair of appendages, suggests that xenusians like this organism ...

''. Occasionally mis-spelt ''Magadictyon''. Megadictyon is a large lobopodian, with body length (excluding appendages) possibly up to 20 centimeters in total. The head has a pair of robust frontal appendages associated with rows of spine and terminal claws. Underside the head is a

radiodont Radiodonta is an extinct order of stem-group arthropods that was successful worldwide during the Cambrian period. They may be referred to as radiodonts, radiodontans, radiodontids, anomalocarids, or anomalocaridids, although the last two origi ...

-like mouthpart forming by multiple layers of plates and teeth-like structures. The trunk is wide and annulated, with a pair of well-developed lobopodous limbs on each body segment. Only 8 segment/limb pairs are countable in the incomplete fossil materials which lacking posterior region, so it may have had more (possibly up to 11 to 13) in nature. It also has pairs of digestive glands similar to those of basal

arthropod Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and cuticle made of chitin, ...

References

Lobopodia {{paleo-protostome-stub