Applying morphometrics to early land plant systematics: A new <i>Leclercqia</i> (Lycopsida) species from Washington State, USA
Bibliographic record
Abstract
PREMISE OF THE STUDY: Early land plant fossils can be challenging to interpret due to their morphological simplicity and often fragmentary nature. Morphometric techniques using commonly preserved characters might increase diagnostic value of such material. To evaluate the utility of morphometrics in assessing morphospecies boundaries in the Devonian, we compared degrees of variation within the cosmopolitan lycopsid genus Leclercqia with that of living relatives (Lycopodium-Spinulum spp.) Of particular interest was determining whether a new morphotype of Leclercqia from the Middle Devonian Chilliwack flora of Washington State fell within or outside the range of variation of previously described species. METHODS: Morphological variation of Leclercqia was assessed across the geographic range of the genus using six vegetative and three reproductive characters. The new morphotype and two previously described species (L. complexa, L. andrewsii) were compared using linear discriminant analysis (LDA). Extant Lycopodium-Spinulum species and variants were similarly analyzed to assess inter- vs. intraspecific variation in living lycopsids. KEY RESULTS: The LDA comparisons of Lycopodium-Spinulum yielded notable morphological disparity between species but substantial overlap between intraspecific variants. Among the fossils, LDA separates the new morphotype, Leclercqia complexa, and L. andrewsii to a similar degree as Lycopodium and Spinulum species. Based on these results and further study, we describe a new species of Leclercqia: Leclercqia scolopendra Benca et Strömberg sp. nov. CONCLUSIONS: Morphometric analyses can aid in informing taxonomic assignment of fragmentary early land plant fossils using readily preserved features, even in the absence of reproductive structures. Applications of this approach to the Chilliwack flora suggest Leclercqia displayed greater morphological variation, taxonomic diversity, and biogeographic extent than previously thought.
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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 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".