Pectoral girdle and forelimb musculoskeletal function in the echidna (Tachyglossus aculeatus): insights into mammalian locomotor evolution
Although evolutionary transformation of the pectoral girdle and forelimb appears to have had a profound impact on mammalian locomotor and ecological diversity, both the sequence of anatomical changes and the functional implications remain unclear. Monotremes can provide insight into an important sta...
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| Format: | Article |
| Language: | English |
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The Royal Society
2018-01-01
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| Series: | Royal Society Open Science |
| Subjects: | |
| Online Access: | https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.181400 |
| _version_ | 1819015880885927936 |
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| author | Sophie Regnault Stephanie E. Pierce |
| author_facet | Sophie Regnault Stephanie E. Pierce |
| author_sort | Sophie Regnault |
| collection | DOAJ |
| description | Although evolutionary transformation of the pectoral girdle and forelimb appears to have had a profound impact on mammalian locomotor and ecological diversity, both the sequence of anatomical changes and the functional implications remain unclear. Monotremes can provide insight into an important stage of this evolutionary transformation, due to their phylogenetic position as the sister-group to therian mammals and their mosaic of plesiomorphic and derived features. Here we build a musculoskeletal computer model of the echidna pectoral girdle and forelimb to estimate joint ranges of motion (ROM) and muscle moment arms (MMA)—two fundamental descriptors of biomechanical function. We find that the echidna's skeletal morphology restricts scapulocoracoid mobility and glenohumeral flexion–extension compared with therians. Estimated shoulder ROMs and MMAs for muscles crossing the shoulder indicate that morphology of the echidna pectoral girdle and forelimb is optimized for humeral adduction and internal rotation, consistent with limited in vivo data. Further, more muscles act to produce humeral long-axis rotation in the echidna compared to therians, as a consequence of differences in muscle geometry. Our musculoskeletal model allows correlation of anatomy and function, and can guide hypotheses regarding function in extinct taxa and the morphological and locomotor transformation leading to therian mammals. |
| first_indexed | 2024-12-21T02:38:46Z |
| format | Article |
| id | doaj.art-d6483cbc918444abb0e7487aee3884df |
| institution | Directory Open Access Journal |
| issn | 2054-5703 |
| language | English |
| last_indexed | 2024-12-21T02:38:46Z |
| publishDate | 2018-01-01 |
| publisher | The Royal Society |
| record_format | Article |
| series | Royal Society Open Science |
| spelling | doaj.art-d6483cbc918444abb0e7487aee3884df2022-12-21T19:18:44ZengThe Royal SocietyRoyal Society Open Science2054-57032018-01-0151110.1098/rsos.181400181400Pectoral girdle and forelimb musculoskeletal function in the echidna (Tachyglossus aculeatus): insights into mammalian locomotor evolutionSophie RegnaultStephanie E. PierceAlthough evolutionary transformation of the pectoral girdle and forelimb appears to have had a profound impact on mammalian locomotor and ecological diversity, both the sequence of anatomical changes and the functional implications remain unclear. Monotremes can provide insight into an important stage of this evolutionary transformation, due to their phylogenetic position as the sister-group to therian mammals and their mosaic of plesiomorphic and derived features. Here we build a musculoskeletal computer model of the echidna pectoral girdle and forelimb to estimate joint ranges of motion (ROM) and muscle moment arms (MMA)—two fundamental descriptors of biomechanical function. We find that the echidna's skeletal morphology restricts scapulocoracoid mobility and glenohumeral flexion–extension compared with therians. Estimated shoulder ROMs and MMAs for muscles crossing the shoulder indicate that morphology of the echidna pectoral girdle and forelimb is optimized for humeral adduction and internal rotation, consistent with limited in vivo data. Further, more muscles act to produce humeral long-axis rotation in the echidna compared to therians, as a consequence of differences in muscle geometry. Our musculoskeletal model allows correlation of anatomy and function, and can guide hypotheses regarding function in extinct taxa and the morphological and locomotor transformation leading to therian mammals.https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.181400biomechanicsmodelglenohumeralmonotremerange of motionmoment arm |
| spellingShingle | Sophie Regnault Stephanie E. Pierce Pectoral girdle and forelimb musculoskeletal function in the echidna (Tachyglossus aculeatus): insights into mammalian locomotor evolution Royal Society Open Science biomechanics model glenohumeral monotreme range of motion moment arm |
| title | Pectoral girdle and forelimb musculoskeletal function in the echidna (Tachyglossus aculeatus): insights into mammalian locomotor evolution |
| title_full | Pectoral girdle and forelimb musculoskeletal function in the echidna (Tachyglossus aculeatus): insights into mammalian locomotor evolution |
| title_fullStr | Pectoral girdle and forelimb musculoskeletal function in the echidna (Tachyglossus aculeatus): insights into mammalian locomotor evolution |
| title_full_unstemmed | Pectoral girdle and forelimb musculoskeletal function in the echidna (Tachyglossus aculeatus): insights into mammalian locomotor evolution |
| title_short | Pectoral girdle and forelimb musculoskeletal function in the echidna (Tachyglossus aculeatus): insights into mammalian locomotor evolution |
| title_sort | pectoral girdle and forelimb musculoskeletal function in the echidna tachyglossus aculeatus insights into mammalian locomotor evolution |
| topic | biomechanics model glenohumeral monotreme range of motion moment arm |
| url | https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.181400 |
| work_keys_str_mv | AT sophieregnault pectoralgirdleandforelimbmusculoskeletalfunctionintheechidnatachyglossusaculeatusinsightsintomammalianlocomotorevolution AT stephanieepierce pectoralgirdleandforelimbmusculoskeletalfunctionintheechidnatachyglossusaculeatusinsightsintomammalianlocomotorevolution |