{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/120565"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/120565","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Morphological and functional consequences of the land-to-water transition in the salamander families Ambystomatidae and Plethodontidae","abstract":"Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2025-05-01","abstract_html":"Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2025-05-01","abstract_has_math":false,"creators":["Darcy, Hannah Elizabeth"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Biology","degree_department":null,"school":null,"contributors":["Anderson, Philip SL","Kawano, Sandy","Roseman, Charles","Suarez, Andrew"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2023,"date_issued":"2023-05","date_published":"2023-05","updated_at":"2026-07-22T22:24:57Z","subjects":["Morphology","Salamanders","Secondarily Aquatic","Morphometrics","Nanoindentation","Finite Element Analysis"],"languages":["en","eng"],"rights":["Copyright 2023 Hannah Darcy"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/2142/120565","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Anderson, Philip SL","Kawano, Sandy","Roseman, Charles","Suarez, Andrew"]},{"key":"dc:creator","label":"Author","values":["Darcy, Hannah Elizabeth"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2023-05","2023-04-26"]},{"key":"dc:type","label":"Dc Type","values":["text","Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Morphology","Salamanders","Secondarily Aquatic","Morphometrics","Nanoindentation","Finite Element Analysis"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en","eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2023 Hannah Darcy"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://hdl.handle.net/2142/120565"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2025-05-01","The student, Hannah Darcy, accepted the attached license on 2023-04-26 at 12:57.","The student, Hannah Darcy, submitted this Dissertation for approval on 2023-04-26 at 12:57.","This Dissertation was approved for publication on 2023-04-26 at 15:28.","DSpace SAF Submission Ingestion Package generated from Vireo submission #19192 on 2023-09-01 at 17:21:55","Land-to-water transitions are major evolutionary events and introduce new constraints to tetrapod morphology. Two North American salamander groups have recolonized aquatic habitats: mole salamanders (Ambystomatidae) and lungless salamanders (Spelerpini; Plethodontidae). I examined the morphological and biomechanical consequences of this transition using a comparative approach. First, I tested the hypothesis that aquatic species have convergent skull morphologies, given the different developmental pathways followed by the two groups. Using 3D microCT scan data from online repositories and museum specimens, I performed a geometric morphometric analysis on skull shape and applied a phylomorphospace to the morphometric data to determine whether morphological variation was due to phylogeny or ecology. Second, I performed nanoindentation tests on cartilage and bone from dissected Ambystoma to determine if Young’s modulus differed significantly between aquatic and terrestrial taxa, and to determine the difference in magnitude between cartilage and bone. Finally, to focus more closely on a structure primarily involved in feeding, I examined the mandibular morphology and functional performance in the two families. I tested the importance of morphology and Young’s modulus values in the mandible in resisting forces that simulated prey-capture by holding shape volume and applied loads constant in a Finite Element Model. While there are statistically significant differences in the jaw proportions in aquatic and terrestrial salamanders in both families, the mechanical models did not support that terrestrial morphologies are better suited for applying bite forces. The results of these four studies will guide future work investigating the functional demands on salamander skulls and what structural changes occur when terrestrial species recolonize aquatic habitats."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Morphological and functional consequences of the land-to-water transition in the salamander families Ambystomatidae and Plethodontidae"]}]}],"canonical_facts":{"dc:contributor":["Anderson, Philip SL","Kawano, Sandy","Roseman, Charles","Suarez, Andrew"],"dc:creator":["Darcy, Hannah Elizabeth"],"dc:date":["2023-05","2023-04-26"],"dc:description":["Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2025-05-01","The student, Hannah Darcy, accepted the attached license on 2023-04-26 at 12:57.","The student, Hannah Darcy, submitted this Dissertation for approval on 2023-04-26 at 12:57.","This Dissertation was approved for publication on 2023-04-26 at 15:28.","DSpace SAF Submission Ingestion Package generated from Vireo submission #19192 on 2023-09-01 at 17:21:55","Land-to-water transitions are major evolutionary events and introduce new constraints to tetrapod morphology. Two North American salamander groups have recolonized aquatic habitats: mole salamanders (Ambystomatidae) and lungless salamanders (Spelerpini; Plethodontidae). I examined the morphological and biomechanical consequences of this transition using a comparative approach. First, I tested the hypothesis that aquatic species have convergent skull morphologies, given the different developmental pathways followed by the two groups. Using 3D microCT scan data from online repositories and museum specimens, I performed a geometric morphometric analysis on skull shape and applied a phylomorphospace to the morphometric data to determine whether morphological variation was due to phylogeny or ecology. Second, I performed nanoindentation tests on cartilage and bone from dissected Ambystoma to determine if Young’s modulus differed significantly between aquatic and terrestrial taxa, and to determine the difference in magnitude between cartilage and bone. Finally, to focus more closely on a structure primarily involved in feeding, I examined the mandibular morphology and functional performance in the two families. I tested the importance of morphology and Young’s modulus values in the mandible in resisting forces that simulated prey-capture by holding shape volume and applied loads constant in a Finite Element Model. While there are statistically significant differences in the jaw proportions in aquatic and terrestrial salamanders in both families, the mechanical models did not support that terrestrial morphologies are better suited for applying bite forces. The results of these four studies will guide future work investigating the functional demands on salamander skulls and what structural changes occur when terrestrial species recolonize aquatic habitats."],"dc:format":["application/pdf"],"dc:identifier":["https://hdl.handle.net/2142/120565"],"dc:language":["en","eng"],"dc:rights":["Copyright 2023 Hannah Darcy"],"dc:subject":["Morphology","Salamanders","Secondarily Aquatic","Morphometrics","Nanoindentation","Finite Element Analysis"],"dc:title":["Morphological and functional consequences of the land-to-water transition in the salamander families Ambystomatidae and Plethodontidae"],"dc:type":["text","Thesis"],"thesis:degree_discipline":["Biology"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:24:57Z"}