Systematics, Phylogenetics, and Biogeography of Early Mississippian Camerate Crinoids of the Nunn Member, Lake Valley Formation, in south-central New Mexico
Bibliographic record
Abstract
The Lake Valley Formation has long been known for the crinoids that are abundant in the formation. The crinoids were noted in the first descriptions of the formations in the late 1800's, but there has never been a comprehensive study done on the crinoids and as a result there is no complete list of crinoids that existed in south-central New Mexico during the Early Mississippian. Although all subclasses of crinoids are found in the Nunn Member, it is the camerate crinoids that dominate the fauna and will be the focus of this study. Most of the specimens studied came from the Macurda collection from the University of Michigan. This collection was supplemented with specimens from the Laudon collection from the University of New Mexico and additional samples collected in the field. These collections provided more than 7000 specimens to be examined, with approximately 4500 of those being identifiable camerate crinoids.;The first chapter of this paper is a systematic review of the camerates. Sixty-one species are recorded from the Nunn Member, five of which are new species: Blairocrinus macurdai, Iotacrinus novamexicana , Agaricocrinus alamogordoensis, Uperocrinus kuesi, and Collicrinus laudoni. An updated list of camerates found in the Lake Valley allows for better understanding and easier comparison of crinoid faunas across North America during this time. Environmental preferences were also examined to see if there was a difference between the faunas found in the shallow water shelf and those found associated with Waulsortian mounds in deeper water.;The majority of the camerates found in the Lake Valley Formation are from the Family Actinocrinitidae. This family has been a source of much taxonomic confusion due to generic concepts not equally applied between Europe in North America. The second chapter of this paper objectively defines the actinocrinitids by discrete characters and reevaluates the generic assignments of North American species. A phylogenetic hypothesis is presented for the relationships of the Actinocrinitidae genera based on a parsimony-based analysis and plotted against stratigraphic ranges. Although groupings were revealed in this analysis, the Actinocrinitidae cannot be readily divided into subfamilies. Twenty-one genera of Actinocrinitidae are described, 17 of which are found in North America. A total of 125 species were evaluated of which 34 species and one open-nomenclature taxon are reassigned to different genera, and four species are designated as nomina dubia.;The third chapter evaluates the similarities of camerate genera in three coeval North American formations with the Lake
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".