Search results
Results From The WOW.Com Content Network
A uniramous limb comprises a single series of segments attached end-to-end. A biramous limb, however, branches into two, and each branch consists of a series of segments attached end-to-end. The external branch (ramus) of the appendages of crustaceans is known as the exopod or exopodite, while the internal branch is known as the endopod or ...
This pair is generally uniramous, but is biramous in crabs and lobsters and remipedes. The pair attached to the second segment are called secondary antennae or simply antennae. The second antennae are plesiomorphically biramous, but many species later evolved uniramous pairs. [2]
Also present on the head were four closely spaced pairs of appendages, the first three of which were uniramous, while the last was biramous. The three uniramous appendages had six segments (podomeres), each ending with a terminal claw, with the endopod of the fourth limb having a similar morphology. The trunk was divided up into 10 segments ...
Appendages may become uniramous, as in insects and centipedes, where each appendage comprises a single series of segments, or it may be biramous, as in many crustaceans, where each appendage branches into two sections. Triramous (branching into three) appendages are also possible. [1]
The first pair of head limbs were biramous antennae, with around 400 annulations on the longer ramus. The next four pairs were all relatively similar, with around 15 short podomeres, each with a stout spine. These appendages appear to have been uniramous, and what seems to be the fifth pair shows bunches of smaller, inward-facing spines.
The name Uniramia was temporarily rejected as a polyphyletic group, but when used now refers to the subphylum consisting of the insects + myriapods. Subphylum Uniramia is characterized by uniramous (single-branching) appendages, one pair of antennae and two pairs of mouthparts (single pairs of mandibles and maxillae). Their body forms and ...
Martinssonia is a small (roughly 1.5 mm long) arthropod, with eight pairs of appendages and ten segments including the eyeless head. It has a pair of antennae, twelve biramous appendages on its head and front two body segments and a final pair of uniramous appendages on its third segment.
Crustacean appendages are typically biramous, meaning they are divided into two parts; this includes the second pair of antennae, but not the first, which is usually uniramous, the exception being in the Class Malacostraca where the antennules may be generally biramous or even triramous.