Journal article
The Early Ordovician bathyurid trilobites Licnocephala and Ibexocephala
Journal of paleontology, Vol.98(4), pp.658-685
07/2024
DOI: 10.1017/jpa.2024.10
Appears in UI Libraries Support Open Access
Abstract
Revision of the type species of the Early Ordovician (Tulean, late Tremadocian) bathyurid trilobite Licnocephala Ross, 1951 demonstrates that it has significantly different morphology than that ascribed to it in the earlier literature, which was based largely on species now assigned to a different genus. In addition to the type species, L. bicornuta Ross, 1951, which is fully revised on the basis of new material, four species, all apparently new, have been recovered, two of which, L. ngi n. sp. and L. bradleyi n. sp., are well enough known to formally name. The overall phylogenetic structure of bathyurids is yet to be determined, but several apparent clades can now be recognized and are discussed. Among these is what is termed the “ Chapmanopyge group,” including Chapmanopyge Fortey and Bruton, 2013, Punka Fortey, 1979, Uromystrum Whittington, 1953, and Licnocephala . These genera are united in the occurrence of much of the anterior cephalic border on the librigenal anterior projection, with most of the anterior margin of the cranidium representing the suture, the possession of very short (exsag.) strap-like posterior cranidial projections, and extremely narrow visual surfaces. A fifth genus of the group, Ibexocephala n. gen., is represented by two new species, I. lossoae (type species) and I. dekosterae . The taxon features a remarkable cranidial morphology involving a strong deflection of the posteriormost part of the cranidium from the anterior part in sagittal profile.
UUID: http://zoobank.org/ab9a8796-84c7-48b1-b0e5-84a22511a6b4
Details
- Title: Subtitle
- The Early Ordovician bathyurid trilobites Licnocephala and Ibexocephala
- Creators
- Jonathan M. Adrain - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Journal of paleontology, Vol.98(4), pp.658-685
- DOI
- 10.1017/jpa.2024.10
- ISSN
- 0022-3360
- eISSN
- 1937-2337
- Publisher
- Cambridge University Press
- Grant note
- National Science Foundation: EAR 9973065, EAR 0308685, DEB 0716065
Fieldwork has been funded by National Science Foundation grants EAR 9973065, EAR 0308685, and DEB 0716065. S. Westrop collaborated on section logging and most of the sampling. E. Landing measured Section HC5 and logged both of the Garden City Formation sections. N. McAdams assisted with fieldwork and acid processing. B. Beck, A. Bradley, R. DeKoster, T. Karim, S. Losso, C. Monson, R. Ng, D. Schultz, and M. Spencer assisted in the field. T. Adrain assisted with curation and SUI specimen numbers. I am grateful to M. Webster and an anonymous reviewer for helpful reviews that improved the manuscript.
- Language
- English
- Electronic publication date
- 02/10/2025
- Date published
- 07/2024
- Academic Unit
- Earth and Environmental Sciences
- Record Identifier
- 9984791073702771
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