When did the first known brittle stars appear in history?
The first known brittle stars date from the Early Ordovician period. These ancient creatures diverged from other echinoderms during that time.
Questions about Brittle star
Short answers, pulled from the story.
Where were fossil brittle stars discovered before the 2010s discoveries in the Southern Hemisphere?
Until discoveries in the Agrio Formation of Neuquén Basin in the 2010s, no fossil brittle star was known in the Southern Hemisphere. No brittle star of Cretaceous age was known until recently either.
How do brittle stars move without using tube feet for locomotion?
Vertebral ossicles support five long slender whip-like arms up to 60 cm in length and articulate via ball-and-socket joints controlled by muscles. One arm presses ahead while other four act as two pairs of opposite levers to thrust the body in rapid jerks when disturbed.
What is the primary method of reproduction for West Indian brittle star Ophiocomella ophiactoides?
West Indian brittle star Ophiocomella ophiactoides frequently undergoes asexual reproduction by fission of disk with subsequent regeneration of arms. Fission starts with softening one side of disk initiating furrow deepening widening until extending across disk splitting animal in two.
Which family contains the most species among brittle stars according to current counts?
467 species belong sole family Amphiuridae frail brittle stars living buried sediment leaving arms stream capture plankton. 344 species exist family Ophiuridae.