PRESENCE OF JUVENILE AMMONITES AT LATE CRETACEOUS METHANE SEEPS (WESTERN INTERIOR SEAWAY)

2018 ◽  
Author(s):  
Alison J. Rowe ◽  
◽  
Neil H. Landman ◽  
Matthew P. Garb ◽  
James D. Witts ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
Western Interior Seaway ◽  
Methane Seeps

LATE CRETACEOUS METHANE SEEPS AS HABITATS FOR NEWLY HATCHED AMMONITES

Palaios ◽  
2020 ◽  
Vol 35 (3) ◽  
pp. 151-163 ◽  
Author(s):  
ALISON J. ROWE ◽  
NEIL H. LANDMAN ◽  
J. KIRK COCHRAN ◽  
JAMES D. WITTS ◽  
MATTHEW P. GARB
Keyword(s):  
Late Cretaceous ◽  
Isotope Composition ◽  
Anaerobic Oxidation Of Methane ◽  
Anaerobic Oxidation ◽  
Western Interior Seaway ◽  
Methane Seeps ◽  
Oxidation Of Methane ◽  
Pierre Shale ◽  
Size And Morphology ◽  
Δ13c And Δ18o

ABSTRACT Cold methane seeps were common in the Late Cretaceous Western Interior Seaway of North America. They provided a habitat for a diverse array of fauna including ammonites. Recent research has demonstrated that ammonites lived at these sites. However, it is still unknown if they hatched at the seeps or only arrived there later in ontogeny. To answer this question, we documented the abundance and size distribution of small specimens of Baculites and Hoploscaphites at eight seep sites in the Pierre Shale of South Dakota. The specimens of Hoploscaphites range from 0.8 to 8.1 mm in shell diameter, with most of them falling between 1 and 1.5 mm. The specimens of Baculites range from 0.7 to 19.2 mm in length, with most specimens falling between 6 and 8 mm. The small size and morphology of these specimens indicate that they are neanoconchs, that is, newly hatched individuals that lived for a short time after hatching. We also analyzed the isotope composition (δ13C and δ18O) of 12 small specimens of Baculites and one specimen of Hoploscaphites with excellent shell preservation from one seep deposit. The values of δ13C and δ18O range from -16.3 to -2.5‰ and -3.0 to -0.9‰, respectively. The values of δ18O translate into temperatures of 19–28°C, which are comparable to previous estimates of the temperatures of the Western Interior Seaway. The low values of δ13C suggest that the tiny animals incorporated carbon derived from anaerobic oxidation of 12C-enriched methane into their shells. Evidently, they must have lived in close proximity to seep fluids emerging at the sediment-water interface and the associated microbial food web. However, this may have contributed to their demise if they were exposed to elevated concentrations of H2S derived from the anaerobic oxidation of methane.

scholarly journals Methane seeps as refugia during ash falls in the Late Cretaceous Western Interior Seaway of North America

Geology ◽  
2021 ◽  
Author(s):  
Shannon K. Brophy ◽  
Matthew P. Garb ◽  
Jone Naujokaityte ◽  
James D. Witts ◽  
Neil H. Landman ◽  
...  
Keyword(s):  
North America ◽  
Late Cretaceous ◽  
Global Ocean ◽  
Western Interior Seaway ◽  
Methane Seeps ◽  
Marine Fauna ◽  
Ash Fall ◽  
Environmental Perturbations ◽  
Abundance And Diversity ◽  
Seep Site

Methane seeps host rich biotic communities, forming patchy yet highly productive ecosystems across the global ocean. Persistent hydrocarbon emissions fuel chemosynthetic food webs at seeps. Methane seeps were abundant in the Western Interior Seaway of North America during the Late Cretaceous. This area also experienced intermittent ash falls, which negatively impacted the marine fauna. We propose that methane seeps acted as refugia during these environmental perturbations. We report a laterally continuous bentonite within the upper Campanian Baculites compressus Zone of the Pierre Shale in southwestern South Dakota (USA) that fortuitously cuts across a methane seep deposit. We compare the macroinvertebrate record below and above the bentonite at seep and non-seep sites. Our results reveal that the paleocommunity (measured by abundance and diversity) was largely unaffected by the ash fall at the seep site, whereas it was significantly altered at the non-seep site. Thus, methane seeps in the Western Interior Seaway may have provided refuges or served as oases in the aftermath of severe environmental perturbations.

HABITAT OF JUVENILE AMMONITES AT METHANE SEEPS IN THE LATE CRETACEOUS WESTERN INTERIOR SEAWAY

2017 ◽  
Author(s):  
Alison J. Rowe ◽  
◽  
Neil H. Landman ◽  
Matthew P. Garb ◽  
James D. Witts
Keyword(s):  
Late Cretaceous ◽  
Western Interior Seaway ◽  
Methane Seeps ◽  
Cretaceous Western Interior Seaway

Geochemical evidence (C and Sr isotopes) for methane seeps as ammonite habitats in the Late Cretaceous (Campanian) Western Interior Seaway

2015 ◽  
Vol 134 (2) ◽  
pp. 153-165 ◽  
Author(s):  
J. Kirk Cochran ◽  
Neil H. Landman ◽  
Neal L. Larson ◽  
Kimberly C. Meehan ◽  
Matthew Garb ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
Sr Isotopes ◽  
Western Interior Seaway ◽  
Methane Seeps ◽  
Geochemical Evidence

BIOTIC RESPONSE TO A LATE CRETACEOUS ASH FALL: COMPARATIVE FAUNAL ANALYSES FROM A METHANE SEEP AND NON-SEEP ECOSYSTEM WITHIN THE WESTERN INTERIOR SEAWAY

2018 ◽  
Author(s):  
Shannon K. Brophy ◽  
◽  
Matthew P. Garb ◽  
Neil H. Landman ◽  
James D. Witts ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
Methane Seep ◽  
Western Interior Seaway ◽  
Ash Fall ◽  
Biotic Response

scholarly journals EVOLUTIONARY STASIS, ECOPHENOTYPY, AND ENVIRONMENTAL CONTROLS ON AMMONITE MORPHOLOGY IN THE LATE CRETACEOUS (MAASTRICHTIAN) WESTERN INTERIOR SEAWAY, USA

2019 ◽  
Author(s):  
James D. Witts ◽  
◽  
Neil H. Landman ◽  
Melanie J. Hopkins ◽  
Corinne Myers
Keyword(s):  
Late Cretaceous ◽  
Western Interior Seaway ◽  
Environmental Controls ◽  
Evolutionary Stasis

scholarly journals Endemicity analysis of global Cretaceous dinosaurian faunas

1992 ◽  
Vol 6 ◽  
pp. 132-132
Author(s):  
Thomas R. Holtz
Keyword(s):  
North America ◽  
South America ◽  
Late Cretaceous ◽  
Late Jurassic ◽  
Continental Drift ◽  
Gobi Desert ◽  
Western Interior Seaway ◽  
Faunal Assemblages ◽  
Terrestrial Vertebrate ◽  
Herbivore Communities

It has often been assumed that the intensively studied dinosaur faunal assemblages of western North America and the Gobi Desert of Mongolia and China represent “typical” Late Cretaceous terrestrial vertebrate communities. This assumption has led to a paleoecological scenario in which a global ecological shift occurs from the dominance of high-browsing saurischian (i.e., sauropod) to low-browsing ornithischian (i.e., iguanodontian, marginocephalian, ankylosaurian) herbivore communities. Furthermore, the assumption that the Asiamerican dinosaur faunas are communities “typical” of the Late Cretaceous has forced the conclusion that the sauropod-dominated Argentine population must have been an isolated relict ecosystem of primitive taxa (i.e., titanosaurid sauropods, abelisaurid ceratosaurs). Recent discoveries and reinterpretations of other Late Cretaceous assemblages, however, seriously challenge these assumptions.Paleogeography and paleobiogeography have demonstrated that terrestrial landmasses became progressively fractionated from the Late Jurassic (Kimmeridgian-Tithonian) to the Late Cretaceous (Campanian), owing to continental drift and the development of large epicontinental seas (the Western Interior Seaway, the Turgai Sea, etc.). The Maastrichtian regressions resulted in the reestablishment of land connection between long isolated regions (for example, western and eastern North America). These geographic changes are reflected in changes in the dinosaurian faunas. These assemblages were rather cosmopolitan in the Late Jurassic (Morrison, Tendaguru, and Upper Shaximiao Formations) but became more provincialized throughout the Cretaceous.Cluster analysis of presence/absence data for the theropod, sauropod, and ornithischian clades indicates that previous assumptions for Late Cretaceous dinosaurian paleoecology are largely in error. These analyses instead suggest that sauropod lineages remained a major faunal component in both Laurasia (Europe, Asia) and Gondwana (South America, Africa, India, and Australia). Only the pre-Maastrichtian Senonian deposits of North America were lacking sauropodomorphs. Furthermore, the abelisaurid/titanosaurid fauna of Argentina is, in fact, probably more typical of Late Cretaceous dinosaurian communities. Rather, it is the coelurosaurian/ornithischian communities of Asiamerica (and particularly North America) that are composed primarily of dinosaurs of small geographic distribution. Thus, the Judithian, Edmontonian, and Lancian faunas, rather than being typical of the Late Cretaceous, most likely represent an isolated island-continent terrestrial vertebrate population, perhaps analogous to the extremely isolated vertebrate communities of Tertiary South America. Furthermore, the shift from high-browsing to low-browsing herbivore “dynasties” more likely represents a local event in Senonian North America and does not represent a global paleoecological transformation of Late Cretaceous dinosaur community structure.

Sign in / Sign up

Export Citation Format

Share Document