Episode 1991
Megalograptus
Mon, 2022-Oct-17 00:34 UTC
Length - 4:28
Direct Link
Welcome to featured Wiki of the Day where we read the summary of the featured Wikipedia article every day.
The featured article for Monday, 17 October 2022 is Megalograptus.
Megalograptus is a genus of eurypterid, an extinct group of aquatic arthropods. Fossils of Megalograptus have been recovered in deposits of Katian (Late Ordovician) age in North America. The genus contains five species: M. alveolatus, M. ohioensis, M. shideleri, M. welchi and M. williamsae, all based on fossil material found in the United States. Fossils unassigned to any particular species have also been found in Canada. The generic name translates to "great writing" and originates from the mistaken original belief that Megalograptus was a type of graptolite, often given names ending with "-graptus" (writing).
Megalograptus was a large predatory megalograptid eurypterid, with the largest and best known species, M. ohioensis, reaching lengths of 78 centimeters (2 ft 7 in). Some species were substantially smaller, with the smallest, belonging to a hitherto undetermined species, only growing to about 10 cm (3.9 in) in length. Morphologically, Megalograptus was highly distinct. The two most distinctive features of Megalograptus were its massive and spined forward-facing appendages, far larger than similar structures in other eurypterids, and its telson (the last division of the body). The sharp spike-shaped telson of Megalograptus was not venomous, but it was specialized in that it was surrounded by unique cercal blades, capable of grasping. Certain fossils of three different species, M. ohioensis, M. shideleri and M. williamsae, are so well-preserved that researchers have been able to infer the coloration they might have possessed in life. All three were deduced to have been brown and black in color, with M. ohioensis being darker than the others.
First described by Samuel Almond Miller in 1874, based on fragmentary fossil remains of the species M. welchi, Megalograptus being a graptolite was not formally questioned until 1908, when Rudolf Ruedemann recognized the fossils as eurypterid remains. Megalograptus was noted as being similar to Echinognathus by August Foerste in 1912 and the two genera have been considered closely related since then, and have been grouped together in the Megalograptidae since 1955. In 2015, the genus Pentecopterus was also assigned to the family. Kenneth E. Caster and Erik N. Kjellesvig-Waering revised Megalograptus in 1955, owing to the discovery of more complete fossil material of the new species M. ohioensis. Caster and Kjellesvig-Waering conducted further work on Megalograptus over the following years. In 1964, they named the species M. shideleri and M. williamsae and reclassified the fragmentary eurypterid Ctenopterus alveolatus as a species of Megalograptus.
Megalograptus lived in near-shore marine environments, where it used its large appendages, and possibly its telson and cercal blades, to capture prey. Possible coprolites (fossilized dung) are known from M. ohioensis, which contain fossil trilobite fragments as well as fragments of M. ohioensis itself. This suggests that Megalograptus might have been cannibalistic at times, like many modern chelicerates.
This recording reflects the Wikipedia text as of 00:34 UTC on Monday, 17 October 2022.
For the full current version of the article, see Megalograptus on Wikipedia.
This podcast is produced by Abulsme Productions based on Wikipedia content and is released under a Creative Commons Attribution-ShareAlike License.
Visit wikioftheday.com for our archives, sister podcasts, and swag. Please subscribe to never miss an episode. You can also follow @WotDpod on Twitter.
Abulsme Productions produces the current events podcast Curmudgeon's Corner as well. Check it out in your podcast player of choice.
This has been Joey Neural. Thank you for listening to featured Wiki of the Day.
|
|
Buy WotD Stuff!!
