Results 221 to 230 of about 99,866 (311)

Balancing mechanics and metabolism: Elevational variation in the microanatomy of hummingbird flight muscle

open access: yesThe Anatomical Record, EarlyView.
Abstract Factors varying along elevational gradients impose strong aerodynamic and physiological constraints on powered flight, yet the internal microanatomical variation associated with elevational context in animals under such conditions remains poorly understood.
Juan Camilo Ríos‐Orjuela   +5 more
wiley   +1 more source

Pelvic breadth and juvenile locomotor energetics: Implications for the obstetrical dilemma hypothesis across human growth in past and present humans

open access: yesThe Anatomical Record, EarlyView.
Abstract The obstetrical dilemma hypothesis (ODH) proposes an evolutionary trade‐off between obstetric requirements and locomotor performance. However, whether external pelvic breadth measures influence walking energetics during human growth remains poorly understood.
Guillermo Zorrilla‐Revilla   +4 more
wiley   +1 more source

The “costly son” hypothesis: Sons exacerbate obstetrical dilemmas in humans and other mammals

open access: yesThe Anatomical Record, EarlyView.
Abstract Human childbirth has often been considered uniquely difficult among mammals, yet recent evidence suggests that obstructed labor and fetopelvic disproportion are widespread across placental mammals. Here, we propose the “costly son” hypothesis: because male offspring are typically larger at birth, they impose greater obstetric risk on mothers ...
Nicole D. S. Grunstra   +1 more
wiley   +1 more source

Anatomy and variation in the paraphyletic Mosasaurus lemonnieri assemblage from the Craie phosphatée de ciply, Belgium

open access: yesThe Anatomical Record, EarlyView.
Abstract Nineteenth century excavations of the Ciply‐Malogne Phosphatic Chalk Formation in Hainaut, Belgium, yielded over 50 partial mosasaur skeletons, the majority of which were referred to the species Mosasaurus lemonnieri Dollo, 1889. In the years since, this taxon has experienced a complicated taxonomic history, and its exceptional hypodigm has ...
Henry S. Sharpe   +3 more
wiley   +1 more source

Structure Determination of a Single Bioapatite Crystal from an Archeological Metastatic Cancer Bone - a TEM Case Study. [PDF]

open access: yesACS Omega
Dallos Z   +13 more
europepmc   +1 more source

Redescription of †Eobrasilia coutoi (Metatheria: Polydolopimorphia), a unique sclerocarpophagous metatherian from the Palaeogene of South America: Systematic affinities, and paleoecological and evolutionary implications

open access: yesThe Anatomical Record, EarlyView.
Abstract The ‘Palaeogene strata’ of the Itaboraí Basin (upper Paleocene‐lower Eocene), Southeastern Brazil, has preserved 29 genera and almost 50 species of metatherians (about 65% of its mammalian diversity). Among them, Eobrasilia coutoi Simpson, 1947 is the most enigmatic due to its quite fragmentary nature.
Leonardo M. Carneiro   +10 more
wiley   +1 more source

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