{"corpus_id":85708924,"paper_sha":"9b7b7d989193edf93d589bfeb78efe8d4fe36d3f","doi":"10.1206/0003-0082(2007)3601[1:MDITPS]2.0.CO;2","arxiv_id":null,"pmid":null,"pmcid":null,"mag_id":1866291603,"dblp_id":null,"acl_id":null,"title":"Morphological Diversity in the Postcranial Skeleton of Casamayoran (?Middle to Late Eocene) Notoungulata and Foot Posture in Notoungulates","year":2007,"publication_date":"2007-12-12","venue":"","journal":{"name":null,"pages":"1 - 26","volume":null},"journal_issn":null,"journal_title":null,"publication_types":["Review"],"pubmed_pub_types":null,"s2_fields_of_study":["Biology","Geography"],"reference_count":48,"citation_count":39,"influential_citation_count":7,"is_open_access":true,"arxiv_categories":null,"arxiv_license":null,"arxiv_journal_ref":null,"mesh_headings":null,"chemicals":null,"comments_corrections":null,"source_flags":1,"s2_open_access_pdf_url":null,"s2_open_access_landing_url":null,"s2_open_access_license":null,"s2_open_access_status":null,"pmc_open_access_pdf_url":null,"pmc_open_access_landing_url":null,"pmc_open_access_license":null,"pmc_open_access_status":null,"unpaywall_open_access_pdf_url":null,"unpaywall_open_access_landing_url":null,"unpaywall_open_access_license":null,"unpaywall_open_access_status":null,"abstract":"Abstract Appendicular skeletons of isotemnid notoungulates are described from Cañadón Vaca (Vacan “subage”, Casamayoran South American Land Mammal “Age”, ?middle to late Eocene). Simpson documented three of these, Thomashuxleya externa, Anisotemnus distentus, and Pleurostylodon similis, some 70 years ago, in fashioning a composite isotemnid skeleton, but he did not emphasize their differences from one another. We note variation, especially in the forelimb, that appears to be functionally significant as well as phylogenetically informative. For example, the downwardly curved olecranon, ventrally concave bowing of the ulnar shaft, and orthogonally directed articulation of the elbow joint suggest an erect forelimb stance in Thomashuxleya externa, whereas the forelimbs of Anisotemnus distentus and Pleurostylodon similis show indications of a crouching posture, including ventrally convex bowing of the ulnar shaft with a slight upward curvature of the olecranon, and an elbow joint in which the antebrachium rotated obliquely relative to the humerus. Articular facets on the proximal carpals suggest that the manus of Anisotemnus was habitually extended, indicating a plantigrade stance of the forelimb. Although none of these three taxa have associated hindfoot material, all known Vacan notoungulate astragali have shallow trochlea, well-developed and deep grooves for the flexor hallucis longus, which are separated from the trochlea by a fossa that contains a superior astragalar foramen. An isolated notoungulate pes, not referred to any of the three taxa above, appears to be pentadactyl, having a distinctive, divergent tarsometatarsal joint for its hallux. It also has a shallow trochlea, an astragalar foramen, and a flexor groove, indicating limited rotation of the upper ankle joint. Indeed, a survey of known Casamayoran-aged notoungulate astragali indicates that most taxa had limited mobility at the tibioastragalar joint, in stark contrast to post-Eocene faunas in which nearly all the ungulates had greater rotation of the upper ankle joint and were subcursorial, as evidenced by their longer and deeper trochlear articulation and loss of the astragalar foramen. We suggest that the change from ambulatory- to subcursorial-dominated ungulate faunas across the Eocene-Oliogocene boundary mirrors the changes from brachydont to hypsodont faunas over the same time. Decreased temperatures and rainfall resulting in more open habitats may be related to both morphological evolutionary patterns.","claims":[{"public_id":"cl_f051ccfd2893f6618ab2794faec3f143","status":"active","text":"Articular facets on the proximal carpals indicate a habitually extended manus and a plantigrade stance in Anisotemnus.","confidence":0.95,"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/claims/cl_f051ccfd2893f6618ab2794faec3f143"},{"public_id":"cl_3fdc5919ff2c8b09d0b29fb7138979ca","status":"active","text":"Forelimb anatomy indicates a crouching posture in Anisotemnus distentus and Pleurostylodon similis.","confidence":0.96,"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/claims/cl_3fdc5919ff2c8b09d0b29fb7138979ca"},{"public_id":"cl_3b71538d1ed49be779c4f871f0d85798","status":"active","text":"Forelimb anatomy indicates an erect forelimb stance in Thomashuxleya externa.","confidence":0.98,"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/claims/cl_3b71538d1ed49be779c4f871f0d85798"},{"public_id":"cl_5e2beaeeb02eff9902ce0992a931f9a0","status":"active","text":"Most Casamayoran-aged notoungulate astragali show limited mobility at the tibioastragalar joint, contrasting with post-Eocene ungulates that had greater upper ankle rotation and were subcursorial.","confidence":0.97,"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/claims/cl_5e2beaeeb02eff9902ce0992a931f9a0"},{"public_id":"cl_b544abbaf46a169727a01a271131bdd1","status":"active","text":"The shift from ambulatory-dominated to subcursorial-dominated ungulate faunas across the Eocene-Oligocene boundary parallels the shift from brachydont to hypsodont faunas and may relate to cooler, drier, more open habitats.","confidence":0.82,"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/claims/cl_b544abbaf46a169727a01a271131bdd1"}],"concepts":[{"public_id":"co_07147270cf5647569ae6454cac600ce5","status":"active","name":"Thomashuxleya externa","description":"An isotemnid notoungulate taxon represented by postcranial skeletal material from Cañadón Vaca.","types":["taxon"],"aliases":[],"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/concepts/co_07147270cf5647569ae6454cac600ce5"},{"public_id":"co_1cb76bc2e03b77a2b931ea8378b32f59","status":"active","name":"manus","description":"The hand or distal forelimb segment in tetrapods.","types":["anatomical structure"],"aliases":[],"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/concepts/co_1cb76bc2e03b77a2b931ea8378b32f59"},{"public_id":"co_3b152ca63bd544ad68cf5962f45424ac","status":"active","name":"crouching posture","description":"A limb posture in which the forelimb is held flexed and more obliquely oriented.","types":["functional posture"],"aliases":[],"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/concepts/co_3b152ca63bd544ad68cf5962f45424ac"},{"public_id":"co_4cafa5772d95df0017ef46196d536b26","status":"active","name":"brachydont","description":"A low-crowned tooth condition characteristic of less hypsodont dentitions.","types":["tooth morphology"],"aliases":[],"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/concepts/co_4cafa5772d95df0017ef46196d536b26"},{"public_id":"co_55593b116b971ffd55f91ba113c9eb43","status":"active","name":"Pleurostylodon similis","description":"An isotemnid notoungulate taxon represented by postcranial skeletal material from Cañadón Vaca.","types":["taxon"],"aliases":[],"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/concepts/co_55593b116b971ffd55f91ba113c9eb43"},{"public_id":"co_57cb771efb0a1a8928d82845535370fc","status":"active","name":"plantigrade stance","description":"A posture in which the entire manus or pes rests on the ground.","types":["functional posture"],"aliases":[],"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/concepts/co_57cb771efb0a1a8928d82845535370fc"},{"public_id":"co_5bbac8911dc82efeec9481520d385a00","status":"active","name":"Anisotemnus distentus","description":"An isotemnid notoungulate taxon represented by postcranial skeletal material from Cañadón Vaca.","types":["taxon"],"aliases":[],"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/concepts/co_5bbac8911dc82efeec9481520d385a00"},{"public_id":"co_700c7c40aa8015630bb825d7cef6da75","status":"active","name":"hypsodont","description":"A high-crowned tooth condition associated with more abrasive-diet adaptation.","types":["tooth morphology"],"aliases":[],"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/concepts/co_700c7c40aa8015630bb825d7cef6da75"},{"public_id":"co_93a2f109872e839112addc4cea25de0c","status":"active","name":"Casamayoran-aged notoungulate astragali","description":"Ankle bones of notoungulates from the Casamayoran South American Land Mammal Age.","types":["fossil material"],"aliases":[],"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/concepts/co_93a2f109872e839112addc4cea25de0c"},{"public_id":"co_93cbff4fb06e7351659facb4a5c826b4","status":"active","name":"olecranon","description":"The proximal bony projection of the ulna that forms the lever arm of the elbow.","types":["anatomical structure"],"aliases":[],"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/concepts/co_93cbff4fb06e7351659facb4a5c826b4"},{"public_id":"co_9de1a66a79a44217373c98351c367f9c","status":"active","name":"Eocene-Oligocene boundary","description":"The geologic transition between the Eocene and Oligocene epochs.","types":["geologic interval"],"aliases":[],"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/concepts/co_9de1a66a79a44217373c98351c367f9c"},{"public_id":"co_b2d325df88c58abdfba56cbbdd12929a","status":"active","name":"subcursorial","description":"Locomotor adaptation toward running with limited ankle rotation and elongated trochlear articulation.","types":["locomotor category"],"aliases":[],"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/concepts/co_b2d325df88c58abdfba56cbbdd12929a"},{"public_id":"co_e4b66c3890e936b5604f63aab92cac4a","status":"active","name":"proximal carpals","description":"The wrist bones closest to the forearm, whose articular facets inform hand posture.","types":["anatomical structure"],"aliases":[],"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/concepts/co_e4b66c3890e936b5604f63aab92cac4a"},{"public_id":"co_fd84926ffbcdc6ac8867518ed1cafc00","status":"active","name":"forelimb stance","description":"The functional posture of the front limb during weight-bearing and locomotion.","types":["functional posture"],"aliases":[],"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/concepts/co_fd84926ffbcdc6ac8867518ed1cafc00"},{"public_id":"co_fedebbdede87bb7118700030ac7fcb46","status":"active","name":"tibioastragalar joint","description":"The upper ankle joint between the tibia and astragalus.","types":["anatomical structure"],"aliases":[],"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/concepts/co_fedebbdede87bb7118700030ac7fcb46"}],"external_ids":{"DOI":"10.1206/0003-0082(2007)3601[1:MDITPS]2.0.CO;2","ArXiv":null,"PubMed":null,"PubMedCentral":null,"MAG":1866291603,"DBLP":null,"ACL":null},"open_access":{"is_open_access":true,"pdf_url":null,"landing_url":"https://sah.borca.ai/papers/85708924","source":null,"pdf_url_source":null,"license":null,"reason":"pdf_url_not_indexed"},"reference_availability":{"status":"available","references_indexed":true,"full_text_available":false,"full_text_source":null,"count_basis":"semantic_scholar_metadata","extraction_status":"not_applicable","reason":null},"source":{"provider":"episteme2","base_corpus":"semantic_scholar_dump","freshness_mode":"unknown","basis":["semantic_scholar_metadata","postgres_metadata"],"limits":["paper metadata is based on indexed upstream scholarly datasets","claims and concepts are available only for extracted papers","absence of claims or concepts means no extracted graph data is available in this response"],"status":"available","degraded":false,"degraded_reasons":[],"diagnostics":{"status":"available","degraded":false,"degraded_reasons":[],"metadata_status":"available","graph_status":"available","abstract_status":"available"},"source_flags":1},"paper_id":631687,"paper_uid":"5a031286-8456-4f68-b6af-1bf4e2733315","canonical_identity":{"paper_id":631687,"paper_uid":"5a031286-8456-4f68-b6af-1bf4e2733315","identity_status":"available","lookup_basis":"semantic_scholar_external_id","compatibility_path":"corpus_id"},"url":"https://sah.borca.ai/papers/85708924"}