Arthropleuridea, from Ancient Greek ἄρθρον ( árthron), meaning "joint", and πλευρά ( pleurá), meaning "rib", is an extinct subclass of myriapod that flourished during the Carboniferous period, having first arisen during the Silurian, and perishing in the Cisuralian.
Paleobiology
Arthropleurids lived in the moist
coal swamps that were common at the time and may have
in the undergrowth. They were either
or
. Besides their size, their most distinguishing features were their legs with eight segments (as many as 30 pairs) and extremely tough
. There is no evidence of spiracles, so the animals must have used
or
for respiration.
Most arthropleurideans are thought to have been terrestrial, although, without any known respiratory structure, terrestriality is assumed only by analogy to modern arthropods.
Distribution and size
Arthropleuridea is most famous for
Arthropleura (order Arthropleurida).
trace fossil from
Arthropleura up to 50 cm wide have been found at Joggins, Nova Scotia.
Reaching over 2 meters in length, arthropleurids are among the largest
ever to have lived. The lack of large terrestrial vertebrate predators and the highly
atmosphere at that time probably enabled them to grow so large.
It was previously believed that
Arthropleura became
extinction as the coal swamps dried out.
However, many fossils have been discovered after the Carboniferous rainforest collapse. A more recent proposal is that predation by
and the
aridification of the
equator caused it to become extinct.
has been found from the Upper
Carboniferous of
Europe and
North America.
Eoarthropleura has been found from the Upper Silurian through the Upper Devonian of Europe and North America.
Microdecemplex, of the order Microdecemplicida, was dwarfed by the other Arthropleurideans, at just a few millimeters long. The genus is known from the Middle through Upper Devonian of New York state, USA.
Classification and placement
After several decades of uncertainty, Arthropleuridea was placed within the Diplopoda in the year 2000.
[ However, there is still controversy regarding the relationships of the three orders to living millipede groups.]
See also
-
Archipolypoda, another extinct group of millipedes including the earliest known air-breathing animal
-
Euthycarcinoidea, a group of enigmatic arthropods that may be ancestral to myriapods
-
Colonization of land, major evolutionary stages leading to terrestrial organisms
