Morphological diversity of Carboniferous arthropods and insights on disparity patterns through the Phanerozoic

  title={Morphological diversity of Carboniferous arthropods and insights on disparity patterns through the Phanerozoic},
  author={Andrea Stockmeyer Lofgren and Roy E. Plotnick and Andrea Wagner},
Abstract Previous studies of overall arthropod disparity have compared Cambrian and Recent biotas, without considering taxa of intermediate age. This study explored morphological diversity among Carboniferous arthropods, primarily from the well-known Westphalian Mazon Creek Lagerstätte. Over 100 arthropod species, belonging to 48 orders, were examined. The data set is composed of nearly equal numbers of crustacean, arachnid, and insect species, with lower numbers of merostomes. Trilobites have… 

Restricted morphospace occupancy of early Cambrian reef-building archaeocyaths

Abstract. The evolution of novel morphologies can signify expansion of a clade into new niches. This can be studied in the fossil record by investigating the morphospace occupancy of organisms,

Comparing taxonomic and geographic scales in the morphologic disparity of Ordovician through Early Silurian Laurentian crinoids

Despite of fluctuations in regional crinoid disparity, average within-biofacies disparity was static throughout the Ordovician, deviating only during the Silurian because of the proliferation of the morphologically aberrant myelodactylid crinoids.

Morphospace saturation in the stem-gnathostomes pteraspidiformes heterostracans: an early radiation of a ‘bottom’ heavy clade

This is the first disparity (explored morphospace) versus diversity (number of taxa) analysis of Pteraspidiformes heterostracans using continuous and discrete characters and shows patterns of taxic diversity and morphological disparity are largely consistent.


  • D. Erwin
  • Environmental Science, Geography
  • 2007
Concern with disparity is a question about temporal variation in the production of morphological innovations, a debate over the relative significance of the generation of new morphologies vs. differential probabili- ties of their successful introduction, and the relative importance of constraint, convergence and contingency in the evolution of form.

Trilobita : phylogeny and evolutionary patterns

Important morphological distinctions have been identified between clades, phylogenetically-important character states recognised and temporal patterns of disparity for two higher taxa have been investigated.


A discovery curve is used to document the sampling history of trilobites, which is considered aproxy for Palaeozoic faunas in general and at genus level the sampling record is incomplete, indicating that families should not be used as a proxy for gen- era.

Discrete and continuous character-based disparity analyses converge to the same macroevolutionary signal: a case study from captorhinids

The first comprehensive comparison of diversity and disparity of captorhinids, a group of basal amniotes that is important for understanding the early evolution of high-fiber herbivory, is presented.

The evolution of Metriorhynchoidea (mesoeucrocodylia, thalattosuchia): an integrated approach using geometric morphometrics, analysis of disparity, and biomechanics

This study illustrates the importance of using a varied toolkit of techniques that together with phylogeny, quantitative assessment of diversity, form, and function help elucidate the macroevolutionary pattern of fossil clades.

Wonderful strife: systematics, stem groups, and the phylogenetic signal of the Cambrian radiation

Gould's Wonderful Life (1989) was a landmark in the investigation of the Cambrian radiation, arguing that a number of experimental body plans had evolved only to become extinct, and that the Cambrians was a time of special fecundity in animal design.

Phylogeny, disparity and mass extinction response in the trilobite order Harpetida

The trilobite order Harpetida has long been easily recognized but many unanswered evolutionary questions about the group remain. This work explores the phylogenetic relationships within Harpetida and



Crustacean disparity through the Phanerozoic: comparing morphological and stratigraphic data

  • M. Wills
  • Environmental Science, Geography
  • 1998
Crustaceans provide an excellent subject for a continuous study of disparity (approxiamtely bodyplan variety) from the Cambrian to the Recent, with a range of forms more disparate than the mean of random samples drawn from the pool of all the taxa considered.

Disparity as an evolutionary index: a comparison of Cambrian and Recent arthropods

Disparity is a measure of the range or significance of morphology in a given sample of organisms, as opposed to diversity, which is expressed in terms of the number (and sometimes ranking) of taxa.

The Early Radiation and Relationships of the Major Arthropod Groups

Cladistic analysis of characters of Cambrian and living representatives (excluding Uniramia) shows that trilobites and chelicerates are relatively advanced compared with "crustaceans," and there are doubts whether the latter constitute a national group.

Comparing palynological abundance and diversity: implications for biotic replacement during the Cretaceous angiosperm radiation

Analysis of an updated and expanded database of North American palynological samples from Cretaceous sediments document a rapid increase in angiosperm diversity and abundance within individual fossil palynofloras (represent- ing local/subregional vegetation).

Morphological diversification of Paleozoic crinoids

  • M. Foote
  • Geography, Environmental Science
  • 1995
Although new regions in morphological space were occupied after the Devonian, these were not as extensive as those that had been evacuated prior to the Carboniferous, and discordance between extensive total morphological change and limited net change further supports previous arguments for the impor- tance of morphological constraints in crinoid evolution.


  • R. Lupia
  • Geography, Environmental Science
  • 1999
The observed incongruence between taxonomic diversity and morphological disparity suggests that morphological evolution in pollen was characterized by larger jumps early and smaller jumps later on, and is similar to that found in several groups of marine invertebrates.

Paleozoic record of morphologica diversity in blastozoan echinoderms.

  • M. Foote
  • Environmental Science, Geography
    Proceedings of the National Academy of Sciences of the United States of America
  • 1992
Analysis of discrete morphological characters shows that initial morphological diversification in the echinoderm subphylum Blastozoa was so pronounced that Morphological diversity relative to taxonomic diversity was greatest in the Cambrian, whereas morphological diversity itself was greatestIn the Middle and Upper Ordovician.

Morphological disparity in Ordovician-Devonian crinoids and the early saturation of morphological space

  • M. Foote
  • Environmental Science
  • 1994
Comparison with generic richness reveals that the full range of form was essentially attained by the early part of the Caradocian, long before the time of maximal taxonomic diversity.

Contrasting evolutionary flexibility in sister groups: disparity and diversity in Mesozoic atelostomate echinoids

The finding that the early atelostomate disparity peak coincides with the origin of the orders Holasteroida and Spatangoida lends support to the perception of orders as semi-independent entities in the biological hierarchy and as meaningful proxies for morphological distinctness.

Patterns of morphologic diversification among the Rostroconchia

Various metrics indicate that the pattern is not due to poor sampling of Cambro-Ordovician species and thus merits a biological explanation, and the data do not suggest that morphologic evolution became more constrained among rostroconchs as a whole, but instead suggest a reduced characteristic rate of morphologic change in the clade that happened to survive the end-Ordovan extinction.