An official website of the United States government
The Plio-Pleistocene Pinecrest beds (Tamiami Fm.) of southern Florida rank amongst the most species-rich assemblages known from the Cenozoic macrofossil record. The tropical to subtropical fauna of the Pinecrest beds includes hundreds of mollusk species and subspecies (perhaps over 1,000), as well as diverse corals, bryozoans, and vertebrates. Some elements of the Pinecrest fauna are extant, but most species went extinct during one or more extinction pulses early in the Pleistocene. There was significant species turnover, but perhaps limited overall change in biodiversity relative to the present. Characterization of biotic change during this interval is important for understanding the evolution of the modern molluscan fauna of the southeastern United States but is unfortunately stymied by two major confounding factors. First, there are no natural exposures of the Pinecrest, and detailed sections have only been exposed in now-flooded quarries near Sarasota, Florida. Most samples from these and other quarries and canal cuts come from spoil piles, which often mix shells from multiple time intervals and habitats, limiting stratigraphic and ecological resolution for occurrence records. Second, the mollusks of the Pinecrest have not been comprehensively treated systematically and some elements of the macrofauna have likely been taxonomically over-split, leading to confusion and wariness among researchers about using published records in analyses. Conversely, the micromollusk fauna (<5.5 mm) has been understudied and many new species await description. Refining our understanding of this major regional turnover event is dependent upon a stable taxonomic foundation and supporting specimen occurrence data. Current estimates of diversity from literature and museum datasets do not closely align. Literature from the mid 1990s suggest over 550 species of gastropods and 250 species of bivalves in the Pinecrest beds, but numerous species have been described subsequently, the majority in the gray literature. In contrast to published tallies, over 1,000 and 400 names have been applied, respectively, to Pinecrest gastropods and bivalves in the collections the Florida Museum of Natural History, representing 140 families. Over 280 micromollusk species may also be present in the Pinecrest fauna. We have begun a project to comprehensively refine and substantiate these estimates of biodiversity to better characterize the Plio-Pleistocene turnover event(s) that led to the establishment of the modern fauna. Funding source: This research is supported by NSF DEB 2225014.
more »
« less
LOOK ON THE FOSSIL RECORD OF TURRIDS, YE PALEONTOLOGISTS, AND DESPAIR!
The neogastropod clade Conoidea includes the familiar cone snails (Conidae) and 17 additional families, all but one of which (Cryptoconidae) are extant. There are over 5,000 extant species and 380 genera of Conoidea, all of which are venomous predators. Many conoideans other than Conidae and Terebridae (auger snails) are often called “turrids” and are often characterized by the presence of an indented “turrid notch” at the terminal edge of the shell's sutural ramp. Conoideans have a rich fossil record that extends to the Cretaceous, but a combination of hyperdiversity, subtle differences between species, often small shell size, and taxonomic complexity has resulted in them being little studied, despite their evolutionary success. We have begun to explore the fossil record of conoideans from the Plio-Pleistocene of the southeastern United States as part of a broader project to catalog and document the fossil records of all gastropod and bivalve species from this system. A newly developed database derived from literature and museum collections shows that nearly 200 species-group names have been applied to conoideans (excluding Conidae) from this system, fewer than 10 of which were described in the past 50 years. We present preliminary assessments of the Pliocene to Recent diversity patterns of individual subclades from the Southeast. Preliminary data from the Paleobiology Database demonstrate that occurrences assigned to the conoidean family Turridae from this study region are much less likely to be assigned to species than most other co-occurring mollusk families, with about 56% of occurrences assigned to a species. Online specimen data derived from the Florida Museum of Natural History similarly show that just under 50% of records from this system assigned to Turridae are also assigned to species. Because records unidentified to species are unevenly distributed among molluscan families, attempts to restrict analyses to only records which are well-resolved taxonomically may impact our overall understanding of biodiversity and ecology, especially when they result in the exclusion of species-rich clades. Our results highlight the importance of primary systematic research and museum collections for assessing important but understudied components of the biodiversity of fossil molluscan faunas.
more »
« less
- Award ID(s):
- 2225014
- PAR ID:
- 10479901
- Publisher / Repository:
- Geological Society of America
- Date Published:
- Journal Name:
- Geological Society of America Abstracts with Programs
- Volume:
- 55
- Issue:
- 6
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Leaves are the most abundant and visible plant organ, both in the modern world and the fossil record. Identifying foliage to the correct plant family based on leaf architecture is a fundamental botanical skill that is also critical for isolated fossil leaves, which often, especially in the Cenozoic, represent extinct genera and species from extant families. Resources focused on leaf identification are remarkably scarce; however, the situation has improved due to the recent proliferation of digitized herbarium material, live-plant identification applications, and online collections of cleared and fossil leaf images. Nevertheless, the need remains for a specialized image dataset for comparative leaf architecture. We address this gap by assembling an open-access database of 30,252 images of vouchered leaf specimens vetted to family level, primarily of angiosperms, including 26,176 images of cleared and x-rayed leaves representing 354 families and 4,076 of fossil leaves from 48 families. The images maintain original resolution, have user-friendly filenames, and are vetted using APG and modern paleobotanical standards. The cleared and x-rayed leaves include the Jack A. Wolfe and Leo J. Hickey contributions to the National Cleared Leaf Collection and a collection of high-resolution scanned x-ray negatives, housed in the Division of Paleobotany, Department of Paleobiology, Smithsonian National Museum of Natural History, Washington D.C.; and the Daniel I. Axelrod Cleared Leaf Collection, housed at the University of California Museum of Paleontology, Berkeley. The fossil images include a sampling of Late Cretaceous to Eocene paleobotanical sites from the Western Hemisphere held at numerous institutions, especially from Florissant Fossil Beds National Monument (late Eocene, Colorado), as well as several other localities from the Late Cretaceous to Eocene of the Western USA and the early Paleogene of Colombia and southern Argentina. The dataset facilitates new research and education opportunities in paleobotany, comparative leaf architecture, systematics, and machine learning.more » « less
-
Evans, Alistair; Peecook, Brandon; Bai, Bin; Benito, Juan; Capobianco, Alessio; Chapelle, Kimberley; Chiarenza, Alfio; Davis, Brian; Delcourt, Rafael; Ehret, Dana (Ed.)Interpretations of extinct vertebrate anatomy, behavior, and life history are built upon comparative anatomy data from neontological collections. Ideally, these interpretations are informed by metadata collected while the organism was alive such as diet, mass throughout life, social relationships, and reproductive history. Unfortunately, these data are not available for many specimens as natural history collections have focused on wild-caught individuals for which mass at collection, sex, and collection locality are typically the only associated data. In contrast, extensive life-history data are collected from organisms in sustained human care, but transferring these data from zoos to natural history collections is not standardized or prioritized. The Duke Lemur Center (DLC) has been designing a database that allows researchers access to morphological and life-history data derived from animals that were part of the living research colony. The DLC is home to over 200 lemurs representing 16 different species. The colony has access to open air, multi-acre habitats. For over 50 years the AZA-accredited DLC has been a platform for non-invasive research on strepsirrhine primates and the DLC Museum is the repository for DLC specimens and fossils related to the evolution of primates. The colony’s breeding records, veterinary care, husbandry data, locomotor behaviors, and diets are recorded by researchers and staff. However, these data are disaggregated, making it difficult to explore. The DLC Data Team started by generating microCT scans of the osteology and frozen cadaver collection to make morphological data available on MorphoSource. Preserved specimens were rehoused and inventoried. Now we are using DLC-developed REDCap database management tools to network scans with life-history records, building a database that researchers can use to explore questions such as individual variation in tooth wear, osteological signatures of different pathologies, and individual biomechanical performance. The REDCap database is also used to store fossil metadata like field notes and specimen preparation records. Our goal is to make these database tools available to other living colonies and natural history collections, so life-history data can be shared and standardized across institutions. This effort – in collaboration with the ZooMu network – will ultimately make life histories accessible to researchers – including paleontologists exploring the fossil record.more » « less
-
The Crystal-Wonder Cave System developed in the Western Escarpment of the southern Cumberland Plateau in the Interior Low Plateau karst region of south-central Tennessee, USA is a global hotspot of cave-limited biodiversity. We combined historical literature, museum accessions, and database occurrences with new observations from bio-inventory efforts conducted between 2005 and 2022 to compile an updated list of troglobiotic and stygobiotic biodiversity for the Crystal-Wonder Cave System. The list of cave-limited fauna includes 31 species (23 troglobionts and 8 stygobionts) with 28 and 18 species documented from the Crystal and Wonder caves, respectively, which represents five phyla, ten classes, nineteen orders, and twenty-six families (six arachnids, three springtails, two diplurans, three millipedes, six insects, three terrestrial snails, one flatworm, five crustaceans, and two vertebrates, respectively). The Crystal-Wonder Cave System is the type locality for six species—Anillinus longiceps, Pseudanophthalmus humeralis, P. intermedius, Ptomaphagus hatchi, Tolus appalachius, and Chitrella archeri. The carabid beetle Anillinus longiceps is endemic to the Crystal-Wonder Cave System. Sixteen species are of conservation concern, including twelve taxa with NatureServe conservation ranks of G1–G3. The exceptional diversity of the Crystal-Wonder Cave System has been associated with several factors, including a high dispersal potential of cave fauna associated with expansive karst exposures along the Western Escarpment of the southern Cumberland Plateau, a high surface productivity, and a favorable climate throughout the Pleistocene.more » « less
-
Abstract Most species exhibit morphological stasis following speciation, and this is a key feature of the concept of punctuated equilibria. Stasis results in species often having long durations on geological timescales. Durational data are fundamental to many types of paleobiological analyses and are ideally based on occurrence data represented by specimens in museum collections. Often, however, durational data are presented without supporting information about voucher specimens that document stratigraphic ranges, including first and last appearances. We use the iconic Devonian trilobiteEldredgeops ranato demonstrate that durational data can be challenging to determine at multiple taxonomic levels. Further, we show that different datasets—including Sepkoski’s published databases, the Paleobiology Database, and iDigBio—give discordant results concerning first and last occurrences. We argue that paleontologists should adopt two general best practices to help address these problems. First, systematists should clearly identify voucher specimens that represent stratigraphic occurrences of species. Second, we recommend that high-quality photographs of occurrence vouchers be placed in open access websites and be assigned public domain licensing before being paywalled by journals. Such voucher images also have a role to play in training artificial intelligence (AI) systems that will be applied to future paleobiological questions.more » « less
