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Man with long hair pulled into a low ponytail wears a button down shirt, a vest, and wire rimmed glasses holds a stuffed animal fossil

James Lamsdell

Associate Professor of Geology

Categorized As

Role: Faculty,
Focus or Research Area: Geology,

Paleobiology, Paleontology, Arthropods, Macroevolution, Mass extinction, Macroecology, Paleoecology, Phylogenetics — My research focuses on macroevolution and paleoecology through the lens of paleontology and paleobiology, particularly in aquatic arthropods such as marine chelicerates (relatives of spiders, mites, scorpions etc.). I use phylogenetics to test the relationships of extinct organisms, and with these hypotheses of relationships I test for patterns of selectivity in macroevolutionary events such as mass extinctions. I am particularly interested in the ontogeny of arthropods and how new phenotypes arise through heterochrony.


Paleobiology Lab

My research interests centre around exploring patterns in macroevolution and macroecology through a phylogenetic framework. My work specifically focuses on Palaeozoic arthropods, with a particular focus on aquatic chelicerates (eurypterids and xiphosurans). I have a specific interest in applying phylogenetic methodologies to fossil groups, both in regard to resolving issues of arthropod systematics and in regard to tackling broader macroevolutionary questions, especially surrounding mass extinction events. My work combines phylogenetic and morphometric analyses to quantify patterns of morphological change in response to extinction events and subsequent recoveries, and compares changes in evolutionary rates and ecological preferences to search for selective patterns across these events and subsequent recoveries. With these data I am able to explore how different evolutionary lineages respond to different extinction forcing mechanisms.

Aside from my work on eurypterids and macroevolutionary research, other research interests include: the importance of lagerstätten for informing on arthropod evolution; studying evidence for arthropod development in the fossil record and the role of heterochrony in arthropod evolution, including the importance of ontogenetic data for phylogenetic analyses and calculations of morphospace; the relationship between diversity, morphological disparity, and ecological variety; and the generality of ecological preferences across and within clades.

Current and ongoing research projects

  • Exploring environmental drivers of morphological change through phylogenetic paleoecology (funded via an NSF CAREER award, 2020-2026).
  • Description of new eurypterid, chasmataspidid, and horseshoe crab species from Canada, China, Germany, United Kingdom, and United States of America.
  • Documentation of ontogeny and heterochrony among aquatic chelicerates.
  • Ontogeny and heterochrony of Paleozoic echinoderms, as part of a collaborative project studying evolutionary modes within the group (funded via an NSF award, 2023-2026).

Representative papers

  1. Lamsdell JC, Isotalo PA, Rudkin DM, Martin MJ. 2023. A new species of the Ordovician horseshoe crab Lunataspis. Geological Magazine 160, 167–171.
  2. Lamsdell JC. The conquest of spaces: exploring drivers of morphological shifts through phylogenetic palaeoecology. Palaeogeography, Palaeoclimatology, Palaeoecology 583 (110672), 1–14.
  3. Lamsdell JC. A new method for quantifying heterochrony in evolutionary lineages. Paleobiology 47, 363–384.
  4. Hughes ES, Lamsdell JC. Discerning the diets of sweep-feeding eurypterids: assessing the importance of prey size to survivorship across the Late Devonian mass extinction in a phylogenetic context. Paleobiology 47, 271–283.
  5. Lamsdell JC, McCoy VE, Perron-Feller O, Hopkins MJ. 2020. Air breathing in an exceptionally preserved 340 million year old sea scorpion. Current Biology 30, 4316–4321.

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