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A PHYLOGENETIC ANALYSIS OF FOSSIL AND EXTANT SHRIMP-LIKE DECAPODS (DENDROBRANCHIATA AND CARIDEA)

Sudarsky, Sergio
http://rave.ohiolink.edu/etdc/view?acc_num=kent1472647292

Abstract Details

2016, MS, Kent State University, College of Arts and Sciences / Department of Earth Sciences.
Decapod crustaceans are of particular interest from both historical and modern perspectives due to their great diversity throughout their evolutionary history and as a food resource with great economic importance for both fisheries and aquaculture. The order’s history can be traced back to the Late Devonian, but a good record of their diversity doesn’t exist until the Mesozoic. Decapods, for the most part, have moderate preservation potential, compared to most invertebrate groups, and have a rich fossil record which has allowed systematists to categorize large groups within the order through their evolutionary history and to compute intra-order phylogenies based on very apparent morphological characters. This, however, is not the case for the shrimp-like decapods, which have a significantly lower preservation potential due to their softer exoskeleton. The late Jurassic Solnhofen Laggerstatte in southern Germany has yielded a very diverse and abundant record of shrimp-like decapods, among other animals. The exceptional preservation exhibited by these fossils allows the visualization of even some of the most discreet morphological features. In this work, a phylogenetic analysis was run using both fossil shrimp primarily from the Solnhofen Laggerstatte and extant species of shrimp-like decapods. The purpose of this work is to place both modern and fossil shrimp-like decapod species in a phylogenetic context through the comparison of their morphological characters. We believe this study offers fresh insight on the evolutionary relationships and character polarization within the decapod order. 139 characters (82 binary + 57 multistate; 45 from carapace, 19 from cephalic appendage, 47 from pereiopods, 18 from pleon, 8 from telson, and 2 others) were coded for 100 species (45 fossil + 55 extant). Specimens belong to several collections: The United States National Museum of Natural History, The Carnegie Museum, The Yale Peabody Museum, The Staatliches Naturwissenschaftliche Sammlungen Bayerns, and a private collection in Chicago. Euphausia superba (Dana, 1850) was used as outgroup. The character matrix was generated in Microsoft Excel and Mesquite. Phylogenetic analysis was run in PAUP* 4.0b10. Character history was traced in Mesquite. The current work does not support the monophyly of any currently accepted taxonomic levels within the order except for the dendrobranch superfamilies Penaeoidea and Sergestoidea and the family Aegeridae. The hypothesis that dendrobranchs are the plesiomorphic form for the group is partially supported due to the early branching of the sergestoid clade; however, many dendrobranch character states are considered to be homoplasic since penaeoids do not group together with sergestoids. The monophyly of dendrobranch superfamilies is supported, though the monophyly of family Penaeidae is challenged. The monophyly of carideans as well as caridean superfamilies is challenged in the current work as well. Basal caridean (Atydae, Pasiphaeidae, and Procarididae) family placement with respect to other more derived families in this study is consistent with the results from previous phylogenetic works. The inclusion of fossil species in a decapod shrimp phylogeny offers new insight to the order’s evolutionary history. The difference in the extant only and the comprehensive phylogeny topologies results from different character polarization and clade groupings. This and the fact that nodes in both phylogenies have overall very little support suggests that reevaluation of character designation and species selection is necessary. Characters with too many states, multiple characters describing a single morphological aspect, and characters with unclear functions are some that will be reevaluated. Differential character weighting is also being considered. More taxa will be coded and included in the analysis to yield a more balanced representation of each suborder as well as to represent the morphological variation within each family.
Carrie Schweitzer (Advisor)
Rodney Feldmann (Committee Member)
Neil Wells (Committee Chair)
133 p.
Paleontology
decapod shrimp, phylogeny, fossil, extant, morphology

Recommended Citations

Citations

  • Sudarsky, S. (2016). A PHYLOGENETIC ANALYSIS OF FOSSIL AND EXTANT SHRIMP-LIKE DECAPODS (DENDROBRANCHIATA AND CARIDEA) [Master's thesis, Kent State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=kent1472647292

    APA Style (7th edition)

  • Sudarsky, Sergio. A PHYLOGENETIC ANALYSIS OF FOSSIL AND EXTANT SHRIMP-LIKE DECAPODS (DENDROBRANCHIATA AND CARIDEA). 2016. Kent State University, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=kent1472647292.

    MLA Style (8th edition)

  • Sudarsky, Sergio. "A PHYLOGENETIC ANALYSIS OF FOSSIL AND EXTANT SHRIMP-LIKE DECAPODS (DENDROBRANCHIATA AND CARIDEA)." Master's thesis, Kent State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=kent1472647292

    Chicago Manual of Style (17th edition)

kent1472647292
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© 2016, some rights reserved.Creative Commons License A PHYLOGENETIC ANALYSIS OF FOSSIL AND EXTANT SHRIMP-LIKE DECAPODS (DENDROBRANCHIATA AND CARIDEA) by Sergio Sudarsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. Based on a work at etd.ohiolink.edu.
This open access ETD is published by Kent State University and OhioLINK.