Middle Devonian (Givetian) sharks from Cairo, New York (USA): Evidence of early cosmopolitanism
Bibliographic record
Abstract
Whereas cosmopolitan distribution patterns are established for many Late Devonian vertebrates (e.g., placoderms, onychodontiforms), few palaeobiogeographic studies have considered chondrichthyans. Recent discoveries of shark material demonstrate that some chondrichthyans were cosmopolitan by the Middle Devonian. Abundant Givetian microremains have been recovered from the Cairo quarry in eastern New York State, USA. These include teeth of two shark species with Gondwanan affinities, the omalodontid Portalodus mannoliniae sp. nov. and the antarctilamnid Wellerodus priscus. Abundant teeth of P. mannoliniae sp. nov. are characterized by a smooth diplodont crown, polarized cusps, and a labially oriented base. The teeth demonstrate monognathic heterodonty. The juvenile morph is distinguished from the adult by smaller size, slender cusps, and variation in the shape of the base. W. priscus is represented by rare juvenile teeth. Two groups of scales that show affinity to material from northern (Spain) and East Gondwana (Antarctica) are tentatively attributed to the two described species. Antarctilamnid distribution suggests a north Gondwanan origin and a colonization of the margin of the landmass before dispersing to Laurentia by the Middle Devonian. This material further indicates that vertebrate global dispersal was initiated by the Middle Devonian, and emphasizes earlier palaeogeographic interpretations that the Middle Devonian "Hamilton fauna" of North American Laurussia originated in the Early Devonian in South American Gondwana.
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 distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.038 | 0.005 |
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; both teacher heads agree on what is shown here.
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".