Ordovician [Dobrotivian (Llandeillian Stage) to Ashgill] crinoids (phylum Echinodermata) from the Montes de Toledo and Sierra Morena, Spain with implications for paleogeography of Peri-Gondwana

Abstract

Seven crinoid species and one very unusual column are recognized from the Ordovician, Dobrotivian (Llandeillian Stage) to Ashgill of Spain. Three previously described species, Heviacrinus melendezi Gil Cid, Domínguez, and Silván, 1996; Coralcrinus sarachagorum Gil Cid, Domínguez, and Silván, 1998; and Ortsaecrinus cocae Gil Cid, Domínguez, Torres, and Jiménez, 1999, are considered, and four new species assigned to three new genera are described herein, including Visocrinus castelli, Fresnedacrinus ibericus, Morenacrinus silvani, and Merocrinus millanae. Previous reports of Ramseyocrinus from Spain have been revised, and we agree that this disparid is not presently known from Spain. These crinoids represent the largest Ordovician crinoid fauna from Gondwana, including these localities and those from the Montagne Noire along peri-Gondwana during the Ordovician. The crinoids reported here, from the Montes de Toledo and Sierra Morena, and the Ordovician crinoids from Montagne Noire have very little in common with Ordovician crinoids from the Prague Basin. Thus, these new data support paleogeographic plate positioning that allows for either paleoclimatic, paleoenvironmental, or paleogeographic isolation between the Prague Basin and peri-Gondwana.

A Laurentian Iocrinus Hall (Crinoidea, Disparida) in the Dapingian or Darriwilian (Middle Ordovician, Arenig) of Oman

“…Ausich (in review comments, forwarded to S. K. D. on 18 February 2010) has brought to our attention the similarity of the Oman material to Llanvirn Heviacrinus melendezi Gil Cid, Domínguez Alonso and Silván Pobes, 1996 (see also Ausich et al . 2002, 2007) from Spain, a disparid genus lacking an anal sac.…”

“…Gil Cid et al . (1996, p. 20) originally assigned the genus Heviacrinus to the family Iocrinidae, whereas Ausich et al . (2002, p. 989) moved it to the family Maennilicrinidae Ausich of the order Maennilicrinida Ausich in strict accordance with Ausich’s (1998) system of classification.…”

“…We prefer to call our material Iocrinus (but certainly an iocrinid) and to suggest that Heviacrinus is a primitive member of the Iocrinidae. Furthermore, the Oman specimens differ from H. melendezi in having arms that branch at least seven times (see above) rather than four (Ausich et al . 2002, p. 990) and also have some heterotomous branches, unlike the Spanish taxon.…”

A probable case of heterochrony in the solutan Dendrocystites Barrande, 1887 (Echinodermata: Blastozoa) from the Upper Ordovician of the Prague Basin (Czech Republic) and a revision of the family Dendrocystitidae Bassler, 1938

“…obs. ); Pizarras Cantera Formation, El Viso del Marqués, Ciudad Real Province, Spain (Gil Cid et al 1996, Arroyo & Lara 2002, Ausich et al 2002.…”

Trocholites Conrad, 1838 (Nautiloidea, Tarphycerida) in the Middle Ordovician of the Prague Basin and its palaeobiogeographical significance

“…Thus the presence of Trocholites fugax in the Prague Basin, Iberian Chain and Armorican Massif are coeval, suggesting that faunal exchange took place between these areas during the early Dobrotivian, which is in agreement with the conclusions of Havlíček et al (1994). More recently Ausich et al (2002) described a Dobrotivian echinoderm fauna from the Iberian Chain and suggested that there was faunal isolation between peri-Gondwana and Perunica. In addition, Evans (2000) noted the presence of Trocholites even in the Middle Ordovician of Bolivia, Northwestern Gondwana, but this material has not yet been described nor figured.…”