Project 4942: B. S. Lieberman. 2002. Phylogenetic analysis of some basal Early Cambrian trilobites, the biogeographic origins of the Eutrilobita, and the timing of the Cambrian radiation. Journal of Paleontology. 76 (4):692.
Abstract
This paper presents a phylogenetic analysis of the ''Fallotaspidoidea,'' a determination of the biogeographic origins of the eutrilobites, and an evaluation of the timing of the Cambrian radiation based on biogeographic evidence. Phylogenetic analysis incor-porated 29 exoskeletal characters and 16 ingroup taxa. In the single most parsimonious tree the genus Fallotaspidella Repina, 1961, is the sister taxon of the sutured members of the Redlichiina Richter, 1932. Phylogenetic analysis is also used to determine the evolutionary relationships of two new species of ''fallotaspidoids'' distributed in the White-Inyo Range of California that have been previously illustrated but not described. These species had been referred to Fallotaspis Hupé, 1953, and used to define the occurrence of the eponymous Fallotaspis Zone in southwestern Laurentia. However, these two new species need to be reassigned to Archaeaspis Repina in Khomentovskii and Repina, 1965. They are described as Archaeaspis nelsoni and A. macropleuron. Their phylogenetic status suggests that the Fallotaspis Zone in southwestern Laurentia is not exactly analogous to the Fallotaspis Zone in Morocco, where that division was originally defined. Thus, changes to the biostratigraphy of the Early Cambrian of southwestern Laurentia may be in order. Fur-thermore, specimens of a new species referable to Nevadia Walcott, 1910, are recognized in strata traditionally treated as within the Fallotaspis Zone, which is held to underlie the Nevadella Zone, suggesting further biostratigraphic complexity within the basal Lower Cambrian of southwestern Laurentia. Phylogenetic analyses of the Olenellina and Olenelloidea, along with the phylogenetic analysis presented here, are used to consider the biogeographic origins of the eutrilobites. The group appears to have originated in Siberia. Biogeographic patterns in trilobites, especially those relating to the split between the Olenellid and Redlichiid faunal provinces are important for determining the timing of the Cambrian radiation. Some authors have argued that there was a hidden radiation that significantly predated the Cambrian, whereas others have suggested that the radiation occurred right at the start of the Cambrian. The results from trilobite biogeography presented here support an early radiation. They are most compatible with the notion that there was a vicariance event relating to the origin of the redlichiinid trilobites, and thus the eponymous Redlichiid faunal province, from the ''fallotaspidoids,'' whose representatives were part of the Olenellid faunal province. This vicariance event, based on biogeographic patterns, is likely related to the breakup of Pannotia which occurred sometime between 600–550 Ma, suggesting that the initial episodes of trilobite cladogenesis occurred within that interval. As trilobites are relatively derived arthropods, this suggests that numerous important episodes of metazoan cladogenesis precede both the earliest trilobitic part of the Early Cambrian, and indeed, even the Early Cambrian.Read the article »
Article DOI: 10.1666/0022-3360(2002)076%3C0692:PAOSBE%3E2.0.CO;2
Project DOI: 10.7934/P4942, http://dx.doi.org/10.7934/P4942
This project contains | Matrices |
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Download Project SDD File | Total scored cells: 458 Total media associated with cells: 0 Total labels associated with cell media: 0 |
Characters | |
Total characters: 29 Total characters with associated media: 0 Total characters with media with labels: 0 Total character states: 69 Total character states with associated media: 0 Total character states with media with labels:0 Total unordered/ordered characters:29/0 |
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MorphoBank Project 4942
MorphoBank Project 4942
- Creation Date:
07 November 2023 - Publication Date:
23 November 2023
This research
supported by
Authors' Institutions
- University of Kansas
Members
member name | taxa | specimens | media | chars | character
| cell scorings (scored, NPA, "-") | cell
| rules | ||||||
Shreya Jariwala Project Administrator | 17 | 1 | 1 | 29 | 0 | 0 | 458 (458, 0, 0) | 0 | 0 | 0 |
Taxonomic Overview for Matrix 'M29529' (17 Taxa)
taxon | unscored cells |
scored cells |
no cell support |
NPA cells |
"-" cells | cell images | labels on cell images |
member access |
[1] † Repinella sibirica Taxon name last Modified on 11/07/23 | 6 | 24 | 23 | 0 | 0 | 0 | 0 | 1 |
[2] † Profallotaspis jakutensis Taxon name last Modified on 11/07/23 | 5 | 24 | 24 | 0 | 0 | 0 | 0 | 1 |
[3] † Pelmanaspis jurii Taxon name last Modified on 11/07/23 | 5 | 24 | 24 | 0 | 0 | 0 | 0 | 1 |
[4] † Eofallotaspis tioutensis Taxon name last Modified on 11/07/23 | 6 | 23 | 23 | 0 | 0 | 0 | 0 | 1 |
[5] † Daguinaspis ambroggii Taxon name last Modified on 11/07/23 | 0 | 30 | 29 | 0 | 0 | 0 | 0 | 1 |
[6] † Choubertella spinosa Taxon name last Modified on 11/07/23 | 0 | 29 | 29 | 0 | 0 | 0 | 0 | 1 |
[7] † Fallotaspis typica Taxon name last Modified on 11/07/23 | 3 | 27 | 26 | 0 | 0 | 0 | 0 | 1 |
[8] † Fallotaspis bondoni Taxon name last Modified on 11/07/23 | 0 | 32 | 29 | 0 | 0 | 0 | 0 | 1 |
[9] † Parafallotaspis grata Taxon name last Modified on 11/07/23 | 2 | 27 | 27 | 0 | 0 | 0 | 0 | 1 |
[10] † Archaeaspis hupei Taxon name last Modified on 11/07/23 | 5 | 24 | 24 | 0 | 0 | 0 | 0 | 1 |
[11] † Archaeaspis nelsoni Taxon name last Modified on 11/07/23 | 5 | 24 | 24 | 0 | 0 | 0 | 0 | 1 |
[12] † Archaeaspis macropleuron Taxon name last Modified on 11/07/23 | 5 | 24 | 24 | 0 | 0 | 0 | 0 | 1 |
[13] † Fallotaspidella musatovi Taxon name last Modified on 11/07/23 | 5 | 24 | 24 | 0 | 0 | 0 | 0 | 1 |
[14] † Bigotina bivallata Taxon name last Modified on 11/07/23 | 2 | 30 | 27 | 0 | 0 | 0 | 0 | 1 |
[15] † Lemdadella antarcticae Taxon name last Modified on 11/07/23 | 2 | 29 | 27 | 0 | 0 | 0 | 0 | 1 |
[16] † Lemdadella linaresiae Taxon name last Modified on 11/07/23 | 0 | 30 | 29 | 0 | 0 | 0 | 0 | 1 |
[17] † Olenellina Taxon name last Modified on 11/07/23 | 0 | 33 | 29 | 0 | 0 | 0 | 0 | 1 |