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Convergent Evolution in Enigmatic Trilobites: The Function and Origins of the Harpetid Brim and Trinucleid Fringe
Convergent Evolution in Enigmatic Trilobites: The Function and Origins of the Harpetid Brim and Trinucleid Fringe
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20260202104832
- ISBN
- 9798290924274
- DDC
- 560
- 서명/저자
- Convergent Evolution in Enigmatic Trilobites: The Function and Origins of the Harpetid Brim and Trinucleid Fringe
- 발행사항
- [Sl] : University of Southern California, 2025
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2025
- 형태사항
- 112 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 87-02, Section: B.
- 주기사항
- Advisor: Bottjer, David J.
- 학위논문주기
- Thesis (Ph.D.)--University of Southern California, 2025.
- 초록/해제
- 요약Studying fossil taxa without close living relatives presents unique challenges for paleontologists interested in convergent evolution. Without molecular data to act as an independent assessment of relatedness, convergently similar taxa can be mistaken for near relatives. This problem is compounded when the function of convergently similar structures cannot be adequately constrained because a structure or organism known from the fossil record lacks analogues in the modern. Yet both these difficulties reveal an underlying opportunity to better understand the process of evolution and the history of life on Earth.In trilobites, these challenges and opportunities are exemplified in the order Harpetida and the superfamily Trinucleioidea. These two groups share an unusual morphology, with small bodies, long prolongations, and reduced eyes. Most strikingly of all, derived members of both groups sport a wide pitted and flattened cephalic brim. This structure, known as the 'harpetid brim' or the 'trinucleid fringe', is unlike any structure known in modern arthropods.This work addresses the question of how harpetids and trinucleids arrived at their unusual, shared morphology. First, from a detailed phylogeny of harpetids and trinucleids, it is established that both groups evolved their unusual cephalic brims independently through a process of parallel evolution. The extent to which these groups were subject to similar environmental and evolutionary pressures is then established by comparing their paleobiogeographic ranges and habitat affinities. This approach reveals broad geographic overlap during the Ordovician but suggests that harpetids were less restricted by water depth, while trinucleids were less restricted by sedimentary substrate. This work then explores whether harpetids and trinucleids might have used their brims for the same ecological purpose by empirically testing two functional hypotheses, ultimately concluding that neither hypothesis is well-supported. Finally, the broader lessons that this work has to offer about studying convergent evolution in deep time are considered.
- 일반주제명
- Paleontology
- 일반주제명
- Evolution & development
- 일반주제명
- Paleoecology
- 일반주제명
- Environmental science
- 키워드
- Phylogenetics
- 키워드
- Trilobites
- 기타저자
- University of Southern California Geological Sciences
- 기본자료저록
- Dissertations Abstracts International. 87-02B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
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■00520260202104832
■006m o d
■007cr#unu||||||||
■020 ▼a9798290924274
■035 ▼a(MiAaPQ)AAI32170837
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a560
■1001 ▼aBeech, James Desmond.
■24510▼aConvergent Evolution in Enigmatic Trilobites: The Function and Origins of the Harpetid Brim and Trinucleid Fringe
■260 ▼a[Sl]▼bUniversity of Southern California▼c2025
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2025
■300 ▼a112 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 87-02, Section: B.
■500 ▼aAdvisor: Bottjer, David J.
■5021 ▼aThesis (Ph.D.)--University of Southern California, 2025.
■520 ▼aStudying fossil taxa without close living relatives presents unique challenges for paleontologists interested in convergent evolution. Without molecular data to act as an independent assessment of relatedness, convergently similar taxa can be mistaken for near relatives. This problem is compounded when the function of convergently similar structures cannot be adequately constrained because a structure or organism known from the fossil record lacks analogues in the modern. Yet both these difficulties reveal an underlying opportunity to better understand the process of evolution and the history of life on Earth.In trilobites, these challenges and opportunities are exemplified in the order Harpetida and the superfamily Trinucleioidea. These two groups share an unusual morphology, with small bodies, long prolongations, and reduced eyes. Most strikingly of all, derived members of both groups sport a wide pitted and flattened cephalic brim. This structure, known as the 'harpetid brim' or the 'trinucleid fringe', is unlike any structure known in modern arthropods.This work addresses the question of how harpetids and trinucleids arrived at their unusual, shared morphology. First, from a detailed phylogeny of harpetids and trinucleids, it is established that both groups evolved their unusual cephalic brims independently through a process of parallel evolution. The extent to which these groups were subject to similar environmental and evolutionary pressures is then established by comparing their paleobiogeographic ranges and habitat affinities. This approach reveals broad geographic overlap during the Ordovician but suggests that harpetids were less restricted by water depth, while trinucleids were less restricted by sedimentary substrate. This work then explores whether harpetids and trinucleids might have used their brims for the same ecological purpose by empirically testing two functional hypotheses, ultimately concluding that neither hypothesis is well-supported. Finally, the broader lessons that this work has to offer about studying convergent evolution in deep time are considered.
■590 ▼aSchool code: 0208.
■650 4▼aPaleontology
■650 4▼aEvolution & development
■650 4▼aPaleoecology
■650 4▼aEnvironmental science
■653 ▼aConvergent evolution
■653 ▼aFunctional morphology
■653 ▼aPaleobiogeography
■653 ▼aPhylogenetics
■653 ▼aTrilobites
■690 ▼a0418
■690 ▼a0412
■690 ▼a0426
■690 ▼a0768
■71020▼aUniversity of Southern California▼bGeological Sciences.
■7730 ▼tDissertations Abstracts International▼g87-02B.
■790 ▼a0208
■791 ▼aPh.D.
■792 ▼a2025
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17359087▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
