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Speeds of dinosaurs from the Albian-Cenomanian of Patagonia and sauropod stance and gait

100%

Mazzetta G. V., Blanco R. E.

Acta Palaeontologica Polonica

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2001

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tom 46

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nr 2

Estimates of locomotory speeds of small to large-sized Patagonian dinosaurs are presented for the first time. These estimates are inferred from trackways found on fine to coarse-grained brown sandstones located in the lower section of the Candeleros Member of the Río Limay Formation (Albian-Cenomanian), Neuquén Province, Argentina. The method used is based on the measurement of the stride length (distance between two successive prints of the same foot) and of the length of the hindfoot print, which in turn, allows us to estimate the height at the hip joint and, therefore, the approximate size of the animal. The hypothesis of dynamic similarity implies that the movements of geometrically similar animals, although of different sizes, are dynamically similar only when they move with the same Froude number. The dynamically similar movements (i.e., those with equal Froude number) require equal values of relative stride length (ratio between the stride length and the hip joint height). The relationship between the relative stride length and the Froude number allows us to estimate the speeds of dinosaurs. The dinosaurian ichnofauna studied reveals low speeds that range from 0.5 to 2.6 m s⁻¹. Our analyses show that the sauropods responsible for these trackways were either walking very slowly in a bipedal stance or alternatively they were progressing quadrupedally on a slippery surface.

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A Late Triassic dinosaur-dominated ichnofauna from the Tomanova Formation of the Tatra Mountains, Central Europe

67%

Niedzwiecki G.

Acta Palaeontologica Polonica

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2011

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tom 56

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nr 2

Osteological fossils of dinosaurs are relatively rare in the Late Triassic and Early Jurassic. Thus, ichnofossils are a critical source of information on Late Triassic terrestrial vertebrate communities. The outcrops of the Tomanová Formation (?late Norian–Rhaetian) in the Tatra Mountains of Poland and Slovakia have yielded a diverse ichnofauna. Seven more or less distinct morphotypes of dinosaur tracks have been recognized and are discussed. Most tracks are partly eroded or deformed, but are preserved well enough to be assigned to a range of trackmakers, including early ornithischians, small and large theropods (coelophysoids and/or possibly early tetanurans), and probably basal sauropodomorphs (“prosauropods”) or first true sauropods.

3

First record of the ichnofossil Atollites from the Late Cretaceous of the Northern Apennines, Italy

67%

Serpagli E.

Acta Palaeontologica Polonica

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2005

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tom 50

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nr 2

A new radial trace fossil, Atollites italicum ichnosp. nov., is reported from Upper Cretaceous sediments of the Northern Apennines (Italy). It is made up of several cylinder−club systems, which are interpreted as radiating in a possible faint spiral pattern from a central shaft. The pre−diagenetic reconstruction of the Atollites structure is attempted for the first time. The trace fossil may be attributed to small crustaceans or, less probably, it represents a feeding burrow of other deposit feeders.

Ograniczanie wyników

3 Acta Palaeontologica Polonica

1 Blanco R. E.

1 Mazzetta G. V.

1 Niedzwiecki G.

1 Serpagli E.

1 2011

1 2005

1 2001

Speeds of dinosaurs from the Albian-Cenomanian of Patagonia and sauropod stance and gait

A Late Triassic dinosaur-dominated ichnofauna from the Tomanova Formation of the Tatra Mountains, Central Europe

First record of the ichnofossil Atollites from the Late Cretaceous of the Northern Apennines, Italy