Dinocaridids were bilaterally symmetrical, with a mostly non-mineralized cuticle and a body divided into two major groupings of tagmata (body-sections): head and trunk.
The head comprised only one segment (ocular somite) and had two specialized frontal appendages just in front of the mouth and eyes.
The frontal appendages are either lobopodous (in gilled lobopodians) or arthropodized (in Radiodonta) and usually paired, but highly fused into a nozzle-like structure in Opabinia.
Based on their preocular position and protocerebral origin, the frontal appendages are most likely homologous to the labrum of euarthropods and primary antennae of onychophora.
The trunk possessed multiple segments, each with its own gill branch and swimming flaps (lobes).
It is thought that these flaps moved in an up-and-down motion, in order to propel the animal forward in a fashion similar to the cuttlefish.
In gilled lobopodian genera, the trunk may have borne a lobopodous limb (lobopod) underneath each of the flaps.
The midgut of dinocaridids had paired digestive glands similar to those of siberiid lobopodians and cambrian euarthropods.
Based on the neuroanatomical evidence from Kerygmachela and Lyrarapax, the dinocaridid brain comprised only a protocerebrum, with frontal appendage nerves and optic nerves connected to its anterior and lateral region respectively.
Dinocaridids were bilaterally symmetrical, with a mostly non-mineralized cuticle and a body divided into two major groupings of tagmata (body-sections): head and trunk. The head comprised only one segment (ocular somite) and had two specialized frontal appendages just in front of the mouth and eyes. The frontal appendages are either lobopodous (in gilled lobopodians) or arthropodized (in Radiodonta) and usually paired, but highly fused into a nozzle-like structure in Opabinia. Based on their preocular position and protocerebral origin, the frontal appendages are most likely homologous to the labrum of euarthropods and primary antennae of onychophora. The trunk possessed multiple segments, each with its own gill branch and swimming flaps (lobes). It is thought that these flaps moved in an up-and-down motion, in order to propel the animal forward in a fashion similar to the cuttlefish. In gilled lobopodian genera, the trunk may have borne a lobopodous limb (lobopod) underneath each of the flaps. The midgut of dinocaridids had paired digestive glands similar to those of siberiid lobopodians and cambrian euarthropods. Based on the neuroanatomical evidence from Kerygmachela and Lyrarapax, the dinocaridid brain comprised only a protocerebrum, with frontal appendage nerves and optic nerves connected to its anterior and lateral region respectively.
Dinocaridida