Česká geologická služba
Virtual museum
Home  > Taxonomy > Animals > Metazoans > Arthropods > Merostomates

Merostomata (Merostomates)

      Merostomata is the name given to a grouping of the extinct Eurypterida (sea scorpions) and the Xiphosura (horseshoe crabs). The term was originally used by James Dwight Dana to refer to Xiphosura only, but was emended by Henry Woodward to cover both groups. The name "Merostomata" derives from the Greek roots μηρός (meros, "thigh") and στόμα (stoma, "mouth"), in reference to the animals possession of appendages which are mouthparts at their proximal end, but swimming legs at their distal end. The scientific consensus at the beginning of the twentieth century was that these two marine groups were closely related, and only more distantly related to the terrestrial Arachnida.More recent analyses suggest that the grouping Merostomata is not monophyletic, with Xiphosura being basal to a clade comprising Eurypterida and Arachnida.[3] It is estimated that the Xiphosura diverged from the Arachnida 480 million years ago.The shared features of the two groups traditionally grouped in the Merostomata are now thought to be retentions of primitive conditions (symplesiomorphies), and thus it has been recommended that the name Merostomata be abandoned.

Source: http://en.wikipedia.org/wiki/Merostomata
aglaspis
Img. 70: A comparison of the aglaspidid Aglaspis spinifer with merostomate Kodymirus vagans
merostomata
Img. 70:
Kodymirus vagans Chlupáš et Havlíček, 1965 Ich452
Kodymirus vagans Chlupáš et Havlíček, 1965Chlupáč a Havlíček (1965), Pl. IV, fig. 3, 4 Ich463
Kodymirus vagans Chlupáš et Havlíček, 1965 Ich457
Kodymirus vagans Chlupáš et Havlíček, 1965Chlupáč a Havlíček (1965), Pl. IV, fig. 2 Ich450
Kodymirus vagans Chlupáš et Havlíček, 1965Chlupáč a Havlíček (1965), Pl. VI, fig. 6 Ich470
Kodymirus vagans Chlupáš et Havlíček, 1965Chlupáč a Havlíček (1965), Pl. V, fig. 8 Ich473
Kodymirus vagans Chlupáš et Havlíček, 1965 Ich476
Kodymirus vagans Chlupáš et Havlíček, 1965Chlupáč a Havlíček (1965), Pl. V, fig. 7 Ich480
Kodymirus vagans Chlupáš et Havlíček, 1965Chlupáč a Havlíček (1965), Pl. VI, fig. 3 Ich485
Kodymirus vagans Chlupáš et Havlíček, 1965 Ich487
Kodymirus vagans Chlupáš et Havlíček, 1965Chlupáč a Havlíček (1965), Pl. IV, fig. 5, 6 Ich443
Kodymirus vagans Chlupáš et Havlíček, 1965Chlupáč a Havlíček (1965), Pl. V, fig. 6 Ich465
Kodymirus vagans Chlupáš et Havlíček, 1965 Ich469
Kodymirus vagans Chlupáš et Havlíček, 1965 Ich471
Kodymirus vagans Chlupáš et Havlíček, 1965 Ich481
Kodymirus vagans Chlupáš et Havlíček, 1965 Ich445
Kodymirus vagans Chlupáš et Havlíček, 1965 Ich466
Kodymirus vagans Chlupáš et Havlíček, 1965Chlupáč a Havlíček (1965), Pl. V, fig. 1, 2 Ich477
Kodymirus vagans Chlupáš et Havlíček, 1965 Ich446
Kodymirus vagans Chlupáš et Havlíček, 1965 Ich447

Virtual museum of the Czech Geological Survey, www.geology.cz, (C) Czech Geological Survey, 2011, v.0.99 [13.12.2011]