Systematic revision of the Calmoniidae (Phacopida, Trilobita) from the Devonian Ponta Grossa Formation, Paraná Basin, Brazil

Seventeen nominal species have been recorded among the Calmoniidae (Phacopida, Trilobita) of the Ponta Grossa Formation, Paraná Basin, Brazil. An analysis of 409 specimens from this unit revealed an overestimation of taxonomic diversity, as some of the nominal taxa previously described were based on...

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Autores principales:	Leme, J. M., Mori, A. D., Batista, L. A.
Formato:	Objeto de conferencia Resumen
Lenguaje:	Inglés
Publicado:	2010
Materias:	Ciencias Naturales Paleontología
Acceso en línea:	http://sedici.unlp.edu.ar/handle/10915/16898
Aporte de:	SEDICI (UNLP) de Universidad Nacional de La Plata

id	I19-R120-10915-16898
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spelling	I19-R120-10915-168982023-10-11T20:02:25Z http://sedici.unlp.edu.ar/handle/10915/16898 Systematic revision of the Calmoniidae (Phacopida, Trilobita) from the Devonian Ponta Grossa Formation, Paraná Basin, Brazil Leme, J. M. Mori, A. D. Batista, L. A. 2010 2010 2011-04-13T03:00:00Z en Ciencias Naturales Paleontología Seventeen nominal species have been recorded among the Calmoniidae (Phacopida, Trilobita) of the Ponta Grossa Formation, Paraná Basin, Brazil. An analysis of 409 specimens from this unit revealed an overestimation of taxonomic diversity, as some of the nominal taxa previously described were based on characters derived from taphonomic processes. Some of the individuals used in the diagnosis of these nominal taxa show extensive exfoliation and effacement of the main diagnostic characters, calling for discussion of the status of several species. Thus, Calmonia signifier Clarke differs from C. subseciva Clarke only because it shows a single terminal spine, while in C. subseciva the margin is normally entire. However, in well preserved specimens, minute spines that are similar in shape and position to those of C. signifier can also be observed on the latter. The degree of inflation of the glabellar lobe has been the only character used to distinguish Paracalmonia paranaensis Popp et al. from P. cuspidata (Clarke), but the fact is that P. cuspidata is only known from compressed specimens. P. salamunii (Popp) was based on a sole poorly preserved individual. A character analysis indicates that this specimen fits in C. signifier. The holotype of Parabainella brasiliensis Popp is an exfoliated specimen, hampering thus observation of diagnostic characthers. The monospecific genus Parabainella Popp is distinguished from Bainella Rennie only by the absence of thoracic spines, a character liable of modification by breakage or weathering. Metacryphaeus granulata Popp is characterized only by the presence of glabellar granules. However, smaller granules in trilobites can also be quartz crystals, and therefore probably taphonomic in origin. Thus, following a systematic revision of the Calmoniidae, it appears that at least five nominal species from the Ponta Grossa Formation are invalid. This has important paleoecological and biostratigraphical implications. Sesiones libres Facultad de Ciencias Naturales y Museo Objeto de conferencia Resumen http://creativecommons.org/licenses/by-nc-sa/4.0/ Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) application/pdf
institution	Universidad Nacional de La Plata
institution_str	I-19
repository_str	R-120
collection	SEDICI (UNLP)
language	Inglés
topic	Ciencias Naturales Paleontología
spellingShingle	Ciencias Naturales Paleontología Leme, J. M. Mori, A. D. Batista, L. A. Systematic revision of the Calmoniidae (Phacopida, Trilobita) from the Devonian Ponta Grossa Formation, Paraná Basin, Brazil
topic_facet	Ciencias Naturales Paleontología
description	Seventeen nominal species have been recorded among the Calmoniidae (Phacopida, Trilobita) of the Ponta Grossa Formation, Paraná Basin, Brazil. An analysis of 409 specimens from this unit revealed an overestimation of taxonomic diversity, as some of the nominal taxa previously described were based on characters derived from taphonomic processes. Some of the individuals used in the diagnosis of these nominal taxa show extensive exfoliation and effacement of the main diagnostic characters, calling for discussion of the status of several species. Thus, Calmonia signifier Clarke differs from C. subseciva Clarke only because it shows a single terminal spine, while in C. subseciva the margin is normally entire. However, in well preserved specimens, minute spines that are similar in shape and position to those of C. signifier can also be observed on the latter. The degree of inflation of the glabellar lobe has been the only character used to distinguish Paracalmonia paranaensis Popp et al. from P. cuspidata (Clarke), but the fact is that P. cuspidata is only known from compressed specimens. P. salamunii (Popp) was based on a sole poorly preserved individual. A character analysis indicates that this specimen fits in C. signifier. The holotype of Parabainella brasiliensis Popp is an exfoliated specimen, hampering thus observation of diagnostic characthers. The monospecific genus Parabainella Popp is distinguished from Bainella Rennie only by the absence of thoracic spines, a character liable of modification by breakage or weathering. Metacryphaeus granulata Popp is characterized only by the presence of glabellar granules. However, smaller granules in trilobites can also be quartz crystals, and therefore probably taphonomic in origin. Thus, following a systematic revision of the Calmoniidae, it appears that at least five nominal species from the Ponta Grossa Formation are invalid. This has important paleoecological and biostratigraphical implications.
format	Objeto de conferencia Resumen
author	Leme, J. M. Mori, A. D. Batista, L. A.
author_facet	Leme, J. M. Mori, A. D. Batista, L. A.
author_sort	Leme, J. M.
title	Systematic revision of the Calmoniidae (Phacopida, Trilobita) from the Devonian Ponta Grossa Formation, Paraná Basin, Brazil
title_short	Systematic revision of the Calmoniidae (Phacopida, Trilobita) from the Devonian Ponta Grossa Formation, Paraná Basin, Brazil
title_full	Systematic revision of the Calmoniidae (Phacopida, Trilobita) from the Devonian Ponta Grossa Formation, Paraná Basin, Brazil
title_fullStr	Systematic revision of the Calmoniidae (Phacopida, Trilobita) from the Devonian Ponta Grossa Formation, Paraná Basin, Brazil
title_full_unstemmed	Systematic revision of the Calmoniidae (Phacopida, Trilobita) from the Devonian Ponta Grossa Formation, Paraná Basin, Brazil
title_sort	systematic revision of the calmoniidae (phacopida, trilobita) from the devonian ponta grossa formation, paraná basin, brazil
publishDate	2010
url	http://sedici.unlp.edu.ar/handle/10915/16898
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Systematic revision of the Calmoniidae (Phacopida, Trilobita) from the Devonian Ponta Grossa Formation, Paraná Basin, Brazil

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