کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4747040 1642071 2014 22 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Large dinosaurian tracks from the Upper Cretaceous (Cenomanian–Turonian) portion of the Winton Formation, Lark Quarry, central-western Queensland, Australia: 3D photogrammetric analysis renders the ‘stampede trigger’ scenario unlikely
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فسیل شناسی
پیش نمایش صفحه اول مقاله
Large dinosaurian tracks from the Upper Cretaceous (Cenomanian–Turonian) portion of the Winton Formation, Lark Quarry, central-western Queensland, Australia: 3D photogrammetric analysis renders the ‘stampede trigger’ scenario unlikely
چکیده انگلیسی


• The largest Lark Quarry dinosaur tracks were examined using 3D protocols.
• Many track specimens indicate only minor deterioration since excavation.
• Most original outlines do not resemble actual track morphology.
• Overprinted traces suggest long time lags between large and many small trackmakers.
• Track succession allows for no interaction amid these different sized trackmakers.

The largest dinosaurian tracks at Lark Quarry, central-western Queensland, Australia, were re-examined using revised analytical protocols that incorporate three-dimensional (3D) structure. Comparisons were made with archival photographs, replica specimens (c. 1977) and the in situ tracks (2013) to account for changes to the track surface. Damage caused both during and after the excavation of the tracks was evident, and in cases where the archival photographs and 1970's replicas strongly differ from the in situ tracks, it is apparent that restoration has modified the original track morphology.Even after accounting for recent damage and alteration, several of the track morphologies obtained from new 3D evaluation models differ considerably from the track outlines that were published in the original description of the site. Compared with the new set of representations, some of the original outlines seem to represent simpler, stylized versions of the tracks. A number of the original outlines are >20% larger than the in situ tracks, while others appear to incorporate cracks as part of the margin of digit impressions. Overall, the best-preserved tracks show blunt digit impressions, reaffirming the idea that the trackmaker was a large ornithopod and supporting a reassignment to cf. Iguanodontipus. The new analysis also reveals the nature of the displacement rims associated with the tracks, and the overprinting of these rims by other ichnites—initially by tool marks (presumably caused by floating vegetation) and then by other dinosaurian tracks (assignable to Wintonopus latomorum). In the context of these observations, we see no evidence for an interaction between the cf. Iguanodontipus trackmaker and the smaller-bodied W. latomorum trackmakers, as neither can be inferred to have been present at the tracksite at, or even close to the same time. Similarly, there is no evidence to support the idea that the approach of the cf. Iguanodontipus trackmaker in some way triggered the movement of the W. latomorum trackmakers. Rather than a snap-shot of dinosaurian ‘stampede’, this study supports the idea that Lark Quarry most likely represents a complex time-averaged assemblage of multiple dinosaurian ichnites, preserved over an extended period of time (hours to days) and bracketed by discrete phases of trackmaker activity and fluctuations in water depth.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Cretaceous Research - Volume 51, September 2014, Pages 186–207
نویسندگان
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