TY - CONF
T1 - Placing Naturalis’ Tyrannosaurus Rex specimen in a taphonomic, paleoenvironmental and integrated stratigraphic framework: Hell Creek Formation, Eastern Montana
AU - Kaskes, Pim
AU - Schulp, Anne S.
AU - Larson, Peter L.
AU - Smit, Jan
AU - Kuiper, Klaudia F.
AU - Abels, Hemmo A.
PY - 2016
Y1 - 2016
N2 - From 2018 onwards, the National History Museum of the Netherlands, Naturalis Biodiversity Center in Leiden, will host a new exhibition dedicated to dinosaur paleontology. A relatively complete and extraordinarily well-preserved specimen of Tyrannosaurus rex will form the centerpiece of this gallery. Well over 50% of the skeleton has been recovered, including an articulated skull, left scapula and coracoid, furcula, much of the vertebral column and rib cage, pelvis, right leg and a large part of the tail. The specimen was excavated in 2013 from a fluvial sandstone deposit of the Upper Maastrichtian Hell Creek Formation, c. 50 km southwest of Jordan, eastern Montana, USA. In September 2014, a geological field campaign was conducted to study three aspects of this fossil locality: the taphonomy and sedimentary context (1), the paleoenvironmental conditions (2) and the geological age of the site (3). The unique three-dimensional preservation of this Tyrannosaurus rex specimen can be explained by a very rapid burial shortly after its death, as suggested by the presence of rip-up clasts and climbing ripples at the dig site. Additional grain-size and thermogravimetric analysis show that the skeleton was entombed in a 3.20 m thick body of fine, poorly consolidated, well-sorted sand with a high dolomite content. Furthermore, the sandstone was not compacted, thereby preventing bone deformation. Lastly, the high carbonate content protected the skeleton against subsequent leaching. A paleoenvironmental reconstruction, based on field evidence and pollen analysis, shows that the ecosystem of this Tyrannosaurus rex was characterized by meandering rivers surrounded by densely vegetated floodplains and shallow lakes. The various palynomorph taxa indicate the presence of a high biodiversity, subtropical forest dominated by angiosperms of the Wodehouseia spinata Assemblage Zone. The age of the fossil locality was determined using an integrated stratigraphic approach combining litho-, magneto-, bio- and cyclostratigraphy. Paleomagnetic measurements of the different sections all show a normal polarity that coincides with chron C30N and thereby excludes a stratigraphic position in the upper part of the Hell Creek Formation. Combined with the presence of the palynostratigraphic marker species Aquilapollenites collaris, an age range between c. 66.7 and 67.2 Ma can be established.
AB - From 2018 onwards, the National History Museum of the Netherlands, Naturalis Biodiversity Center in Leiden, will host a new exhibition dedicated to dinosaur paleontology. A relatively complete and extraordinarily well-preserved specimen of Tyrannosaurus rex will form the centerpiece of this gallery. Well over 50% of the skeleton has been recovered, including an articulated skull, left scapula and coracoid, furcula, much of the vertebral column and rib cage, pelvis, right leg and a large part of the tail. The specimen was excavated in 2013 from a fluvial sandstone deposit of the Upper Maastrichtian Hell Creek Formation, c. 50 km southwest of Jordan, eastern Montana, USA. In September 2014, a geological field campaign was conducted to study three aspects of this fossil locality: the taphonomy and sedimentary context (1), the paleoenvironmental conditions (2) and the geological age of the site (3). The unique three-dimensional preservation of this Tyrannosaurus rex specimen can be explained by a very rapid burial shortly after its death, as suggested by the presence of rip-up clasts and climbing ripples at the dig site. Additional grain-size and thermogravimetric analysis show that the skeleton was entombed in a 3.20 m thick body of fine, poorly consolidated, well-sorted sand with a high dolomite content. Furthermore, the sandstone was not compacted, thereby preventing bone deformation. Lastly, the high carbonate content protected the skeleton against subsequent leaching. A paleoenvironmental reconstruction, based on field evidence and pollen analysis, shows that the ecosystem of this Tyrannosaurus rex was characterized by meandering rivers surrounded by densely vegetated floodplains and shallow lakes. The various palynomorph taxa indicate the presence of a high biodiversity, subtropical forest dominated by angiosperms of the Wodehouseia spinata Assemblage Zone. The age of the fossil locality was determined using an integrated stratigraphic approach combining litho-, magneto-, bio- and cyclostratigraphy. Paleomagnetic measurements of the different sections all show a normal polarity that coincides with chron C30N and thereby excludes a stratigraphic position in the upper part of the Hell Creek Formation. Combined with the presence of the palynostratigraphic marker species Aquilapollenites collaris, an age range between c. 66.7 and 67.2 Ma can be established.
M3 - Paper
ER -