Pleistocene paleoecology and feeding behavior of terrestrial vertebrates recorded in a pre-LGM asphaltic deposit at Rancho La Brea, California

Fuller, Benjamin T.; Southon, John; Fahrni, Simon; Farrell, Aisling B.; Takeuchi, Gary T.; Nehlich, Olaf; Guiry, Eric J.; Richards, Michael P.; Lindsey, Emily; Harris, John

doi:10.1016/j.palaeo.2019.109383

Cited by 14 publications

(18 citation statements)

References 43 publications

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“…Determination of fecal pellet age. Hydrocarbon contaminants such as asphaltenes were removed from the pellets to produce radiocarbon dates on bleached holocellulose 22 . Direct radiocarbon dates on two individual pellets yielded 14 C ages of >47,000 years before present (ybp), confirming that these fecal pellets are indeed coprolites and are not the result of modern contamination by invasive Rattus in a highly urbanized area (Table 1).…”

Section: Resultsmentioning

confidence: 99%

“…Unfortunately, paleoclimate inferences from RLB's existing botanical descriptions are currently considered unreliable due to the lack of stratigraphic and taphonomic context (including allochthonous vs. autochthonous origins) for curated isolated specimens 50,51 . There is thus a clear need to develop additional quantitative microclimate and vegetation proxies at RLB, such as the plant macrofossils associated with our stratified C3L7 unit, which are of direct relevance to furthering paleoecological interpretations of vertebrates 13,22 .…”

Section: Uciams # Specimenmentioning

confidence: 99%

“…Vertebrate behavior has been inferred at RLB indirectly via the study of pathologies 12 , morphological proxies (e.g, dental microwear 55 ), and stable isotopes of bone collagen 13,22 and tooth enamel 14 . The coprolites, as the first fossilized diet product at RLB, are thus unique in directly capturing a record of vertebrate behavior: in this case, Neotoma's consumption of leaves and other plant fibers, as evidenced in SEM images of coprolite cross-sections.…”

Section: Uciams # Specimenmentioning

confidence: 99%

“…Stable isotopes of carbon (δ 13 C) are a widely used tool in evaluating the diets and food web linkages of past organisms as it relates to primary producer pathways (e.g., C3 vs. C4 plants). Previous research at RLB has pointed to largely C3 vegetation conditions in the immediate area based on the δ 13 C values of megafauna bone collagen 13,22 . The Neotoma coprolites have a mean δ 13 C of −24.5‰ ± 0.59, suggesting the meals consisted of C3 plants and that the rodents foraged in a closed wooded environment.…”

Section: Uciams # Specimenmentioning

confidence: 99%

“…The Neotoma coprolites have a mean δ 13 C of −24.5‰ ± 0.59, suggesting the meals consisted of C3 plants and that the rodents foraged in a closed wooded environment. Although plant stable isotopes have seldom been studied at RLB, δ 13 C values of a contemporaneous C3 plant, juniper (Juniperus) from 40,140-68,000 years before present have been reported as −19 to −22‰ 57 and a single unidentified piece of "wood" has yielded a δ 13 C value of −20.2‰ from Project 23's Box 1 22 . Correcting for the enrichment between diet item and consumer (a rodent specific feces-diet fractionation of δ 13 C feces-diet = Δ = −3.77‰ 58 ), the RLB Neotoma δ 13 C values could be more consistent with consumption of juniper, Juniperus sp., rather than oak (estimated diet value δ 13 C = −20.73‰; RLB juniper values −19-22‰; P23-39539 oak = −24.4‰).…”

Section: Uciams # Specimenmentioning

confidence: 99%

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Exceptionally preserved asphaltic coprolites expand the spatiotemporal range of a North American paleoecological proxy

Mychajliw

Rice

Tewksbury

et al. 2020

Sci Rep

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As fossilized feces, coprolites represent direct evidence of animal behavior captured in the fossil record. They encapsulate past ecological interactions between a consumer and its prey and, when they contain plant material, can also guide paleoenvironmental reconstructions. Here we describe the first coprolites from the lagerstätte Rancho La Brea (RLB) in Los Angeles, California, which also represent the first confirmed coprolites from an asphaltic (“tar pit”) context globally. Combining multiple lines of evidence, including radiocarbon dating, body size reconstructions, stable isotope analysis, scanning electron microscopy, and sediment analyses, we document hundreds of rodent coprolites found in association with plant material, and tentatively assign them to the woodrat genus Neotoma. Neotoma nests (i.e., middens) and their associated coprolites inform paleoclimatic reconstructions for the arid southwestern US but are not typically preserved in coastal areas due to environmental and physiological characteristics. The serendipitous activity of an asphalt seep preserved coprolites and their original cellulosic material for 50,000 years at RLB, yielding a snapshot of coastal California during Marine Isotope Stage 3. This discovery augments the proxies available at an already critical fossil locality and highlights the potential for more comprehensive paleoenvironmental analyses at other asphaltic localities globally.

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Section: Resultsmentioning

confidence: 99%

Section: Uciams # Specimenmentioning

confidence: 99%

Section: Uciams # Specimenmentioning

confidence: 99%

Section: Uciams # Specimenmentioning

confidence: 99%

Section: Uciams # Specimenmentioning

confidence: 99%

See 3 more Smart Citations

Exceptionally preserved asphaltic coprolites expand the spatiotemporal range of a North American paleoecological proxy

Mychajliw

Rice

Tewksbury

et al. 2020

Sci Rep

Self Cite

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Are geometric morphometric analyses replicable? Evaluating landmark measurement error and its impact on extant and fossil Microtus classification

Fox

Veneracion

Blois

2020

Ecology and Evolution

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Geometric morphometric analyses are frequently employed to quantify biological shape and shape variation. Despite the popularity of this technique, quantification of measurement error in geometric morphometric datasets and its impact on statistical results is seldom assessed in the literature. Here, we evaluate error on 2D landmark coordinate configurations of the lower first molar of five North American Microtus (vole) species. We acquired data from the same specimens several times to quantify error from four data acquisition sources: specimen presentation, imaging devices, interobserver variation, and intraobserver variation. We then evaluated the impact of those errors on linear discriminant analysis‐based classifications of the five species using recent specimens of known species affinity and fossil specimens of unknown species affinity. Results indicate that data acquisition error can be substantial, sometimes explaining >30% of the total variation among datasets. Comparisons of datasets digitized by different individuals exhibit the greatest discrepancies in landmark precision, and comparison of datasets photographed from different presentation angles yields the greatest discrepancies in species classification results. All error sources impact statistical classification to some extent. For example, no two landmark dataset replicates exhibit the same predicted group memberships of recent or fossil specimens. Our findings emphasize the need to mitigate error as much as possible during geometric morphometric data collection. Though the impact of measurement error on statistical fidelity is likely analysis‐specific, we recommend that all geometric morphometric studies standardize specimen imaging equipment, specimen presentations (if analyses are 2D), and landmark digitizers to reduce error and subsequent analytical misinterpretations.

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Paleoecological inferences about the Late Quaternary giant sloths

Dantas,

Campbell,

McDonald

2023

J Mammal Evol

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The Occlusal Surface Area index together with the body mass contribute to better understanding the paleoecology and evolution of the giant sloths in the Americas. The giant sloths from southern South America probably had higher levels of fermentation/lower metabolic requirements, whereas the tropical taxa had higher metabolic requirements. The sloths that dispersed into Central and North America were most likely derived from tropical taxa based on the patterns observed in this study. Relative Muzzle Width and the Hypsodonty indices were used to infer the dietary adaptation of several late Pleistocene/early Holocene giant ground sloths from the Americas. The Nothrotheriidae and Megatheridae taxa were adapted to a browser or mixed-feeder "browser" diet, the Mylodontidae taxa to a variety of dietary types, and the Megalonychidae taxa to a mixed-feeder browser diet. However, these dietary adaptations do not necessarily re ect food niches. In general, Megalonychidae and Nothrotheriidae were climber species, Mylodontidae taxa were digger species, and Megatheriidae taxa were fully terrestrial species.

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Pleistocene paleoecology and feeding behavior of terrestrial vertebrates recorded in a pre-LGM asphaltic deposit at Rancho La Brea, California

Cited by 14 publications

References 43 publications

Exceptionally preserved asphaltic coprolites expand the spatiotemporal range of a North American paleoecological proxy

Exceptionally preserved asphaltic coprolites expand the spatiotemporal range of a North American paleoecological proxy

Are geometric morphometric analyses replicable? Evaluating landmark measurement error and its impact on extant and fossil Microtus classification

Paleoecological inferences about the Late Quaternary giant sloths

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