scholarly journals Dinosaur ichnology and sedimentology of the Chignik Formation (Upper Cretaceous), Aniakchak National Monument, southwestern Alaska; Further insights on habitat preferences of high-latitude hadrosaurs

PLoS ONE ◽  
2019 ◽  
Vol 14 (10) ◽  
pp. e0223471 ◽  
Author(s):  
Anthony R. Fiorillo ◽  
Yoshitsugu Kobayashi ◽  
Paul J. McCarthy ◽  
Tomonori Tanaka ◽  
Ronald S. Tykoski ◽  
...  
Keyword(s):  
High Latitude ◽  
Upper Cretaceous ◽  
Habitat Preferences ◽  
National Monument ◽  
Southwestern Alaska

scholarly journals Δ14C PEAKS APPEARING IN EARLYWOOD AND LATEWOOD TREE RINGS (AD 770–780) IN NORTHEASTERN ARIZONA

Radiocarbon ◽  
2020 ◽  
pp. 1-6
Author(s):  
J H Park ◽  
J Southon ◽  
JW Seo ◽  
P P Creasman ◽  
W Hong ◽  
...  
Keyword(s):  
Tree Rings ◽  
High Latitude ◽  
Pinus Edulis ◽  
Lateral Transfer ◽  
Late Winter ◽  
National Monument ◽  
Small Rise ◽  
Pinyon Pine

ABSTRACT The AD 775 peak in Δ14C (henceforth, M12) was first measured by Miyake et al. and has since been confirmed globally. Here we present earlywood and latewood Δ14C values from tree rings of pinyon pine (Pinus edulis) from Mummy Cave, Canyon de Chelly National Monument, Chinle, Arizona, USA, for the period AD 770–780. These data reconfirm the timing of M12 and show a small rise in Δ14C in AD 774 latewood. Allowing for the delay in lateral transfer of radiocarbon produced at high latitude, this suggests that 14C peak production occurred in late winter or spring of AD 774. Additionally, Δ14C decreased slightly in the earlywood of AD 775 and increased in the latewood of AD 775 to a higher level than that observed in AD 774.

scholarly journals A new hesperornithiform (Aves) specimen from the Late Cretaceous Canadian High Arctic with comments on high-latitude hesperornithiform diet

2016 ◽  
Vol 53 (12) ◽  
pp. 1476-1483 ◽  
Author(s):  
Laura E. Wilson ◽  
Karen Chin ◽  
Stephen L. Cumbaa
Keyword(s):  
Late Cretaceous ◽  
High Latitude ◽  
Upper Cretaceous ◽  
Current Knowledge ◽  
High Arctic ◽  
Time Of Death ◽  
Canadian High Arctic ◽  
Size And Shape ◽  
Devon Island ◽  
Paleoecological Reconstructions

Here we describe a new hesperornithiform specimen from the Upper Cretaceous Kanguk Formation of Devon Island, Nunavut, Canada. This specimen (NUVF 286) is referred to cf. Hesperornis sp. based on size and shape of femora and teeth preserved with other skeletal elements. Previous osteohistologic analyses indicate a subadult ontogenetic stage at the time of death. This new cf. Hesperornis specimen includes the first teeth associated with a high-latitude hesperornithiform, allowing for comments on the trophic behavior of these birds. Paleoecological reconstructions based on current knowledge of polar assemblages and comparisons to modern birds suggest that high-latitude hesperornithiform birds may have had more varied diets than previously assumed.

scholarly journals A diverse Late Cretaceous vertebrate tracksite from the Winton Formation of Queensland, Australia

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11544
Author(s):  
Stephen F. Poropat ◽  
Matt A. White ◽  
Tim Ziegler ◽  
Adele H. Pentland ◽  
Samantha L. Rigby ◽  
...  
Keyword(s):  
Natural History ◽  
Late Cretaceous ◽  
Fossil Record ◽  
Upper Cretaceous ◽  
National Monument ◽  
Eastern Australia ◽  
Sauropod Tracks ◽  
Dinosaur Tracks ◽  
Conservation Park ◽  
Body Fossil

The Upper Cretaceous ‘upper’ Winton Formation of Queensland, Australia is world famous for hosting Dinosaur Stampede National Monument at Lark Quarry Conservation Park, a somewhat controversial tracksite that preserves thousands of tridactyl dinosaur tracks attributed to ornithopods and theropods. Herein, we describe the Snake Creek Tracksite, a new vertebrate ichnoassemblage from the ‘upper’ Winton Formation, originally situated on Karoola Station but now relocated to the Australian Age of Dinosaurs Museum of Natural History. This site preserves the first sauropod tracks reported from eastern Australia, a small number of theropod and ornithopod tracks, the first fossilised crocodyliform and ?turtle tracks reported from Australia, and possible lungfish and actinopterygian feeding traces. The sauropod trackways are wide-gauge, with manus tracks bearing an ungual impression on digit I, and anteriorly tapered pes tracks with straight or concave forward posterior margins. These tracks support the hypothesis that at least one sauropod taxon from the ‘upper’ Winton Formation retained a pollex claw (previously hypothesised for Diamantinasaurus matildae based on body fossils). Many of the crocodyliform trackways indicate underwater walking. The Snake Creek Tracksite reconciles the sauropod-, crocodyliform-, turtle-, and lungfish-dominated body fossil record of the ‘upper’ Winton Formation with its heretofore ornithopod- and theropod-dominated ichnofossil record.

World genera of Mastigitae: review of morphological structures and new ecological data (Coleoptera: Staphylinidae: Scydmaeninae)

Zootaxa ◽  
2018 ◽  
Vol 4453 (1) ◽  
pp. 1 ◽  
Author(s):  
PAWEŁ JAŁOSZYŃSKI
Keyword(s):  
Upper Cretaceous ◽  
Habitat Preferences ◽  
Morphological Characters ◽  
Ecological Data ◽  
Ecological Adaptations ◽  
History Of ◽  
Phylogenetic Hypotheses ◽  
First Time ◽  
Maxillary Palps

Mastigitae comprise most unusual ant-like stone beetles, showing intriguing morphological characters and ecological adaptations. The largest adults among Scydmaeninae can be found in this group; some reaching nearly 9 mm in length, but there are also adults as small as 1.10 mm. Members of Leptomastacini are microphthalmous and depigmented; Mastigini are often black or contrastingly bicolored and have diurnal life style, adults of some species climbing bushes and trees. Papusini inhabit the driest North American deserts and are active during the warmest time of the year; other taxa live in subtropical forests; some are known to enter caves. Adults of some genera have enigmatic modifications of maxillary palps, postgenae or antennae, whose functions still remain unknown. In one genus the male genitalia are enormously elongate, so that these beetles have evolved a method of copulation not known in any other Coleoptera. The evolutionary history of Mastigitae is documented by fossils since the Upper Cretaceous, and extinct forms are even more 'extreme' in their spiny antennae and unusually elongate appendages than their extant relatives. Although phylogenetic hypotheses have been proposed to clarify the relationships and classification of Mastigitae, morphological structures of most genera remain undescribed. They are reviewed in the present synopsis, with detailed descriptions and illustrations of adult structures of all extant genera (Ablepton, Leptomastax, Taurablepton, Mastigus, Palaeostigus, Stenomastigus, Leptochromus, Clidicus and Papusus), with a brief review of known larval forms and fossils. Novel ecological data are given, with emphasis on habitat preferences and feeding behavior. The 'springtail trap' hypothesis for the spiny antennae of Mastigini is rejected, based on field observations and laboratory experiments. For the first time, details of feeding for Palaeostigus and Leptomastax are described. A checklist of species is given, and the main problems related to the classification, phylogeny and ecology of Mastigitae are discussed. 

DINOSAUR ICHNOLOGY AND PALEOENVIRONMENTS FROM THE CHIGNIK FORMATION (ANIAKCHAK NATIONAL MONUMENT, LATE CRETACEOUS, SOUTHWESTERN ALASKA)

2018 ◽  
Author(s):  
Anthony R. Fiorillo ◽  
◽  
Yoshitsugu Kobayashi ◽  
Paul J. McCarthy ◽  
Tomonori Tanaka ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
National Monument ◽  
Southwestern Alaska

scholarly journals The Knife Creek Glaciers of Katmai National Monument, Alaska

1957 ◽  
Vol 3 (22) ◽  
pp. 116-122 ◽  
Author(s):  
Ernest H. Muller ◽  
Henry W. Coulter
Keyword(s):  
Field Data ◽  
Static Condition ◽  
Climatic Conditions ◽  
National Monument ◽  
Snow Line ◽  
Southwestern Alaska

AbstractA group of previously unmapped glaciers on the slopes of Trident and Katmai Volcanoes, southwestern Alaska, was studied for information on the abnormal regimen produced by effects of the 1912 eruption of Mount Katmai. During the eruption an area of 5 square miles (13 km.2) of the summit above regional snow line was destroyed, and the beheaded glaciers were buried under a blanket of pumice and ash. Field data are presented to indicate that the terminus of Fourth Glacier has been essentially stationary since the 1912 eruption. Upper portions of the glacier have thinned, exposing the rim of the caldera which 40 years ago was partly ringed with fringing ice cliffs. Permafrost has developed to within a few feet of the surface of the pumice mantle. Under prevailing climatic conditions Fourth Glacier may be preserved in its present static condition for an indefinite period.

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