Notice bibliographique
Résumé
Abstract Until recently, the chrysophytes were an algal group with mixed affinities and variable morphologies, united largely by their golden brown pigmentation. However, morphological and genetic studies have progressively removed many of the unaffiliated taxa, leaving two closely related classes, the Chrysophyceae sensu stricto and the Synurophyceae. Both the classes contain freshwater and marine species, although are considered more abundant and diverse in oligotrophic waters in terrestrial habitats. Cells may be solitary or colonial, having unequal flagella (heterokont), with flagellar swellings on one or both flagella acting as photoreceptors. Taxa covered by siliceous scales are present in both classes, although silicified bristles are only present in some synurophytes. Some chrysophytes may form cellulosic, chitinous, siliceous or calcareous loricae instead of possessing scales. All taxa from both classes produce resting stages known as stomatocysts, with some species forming them during both asexual and sexual phases. Since stomatocysts, and to a lesser extent scales and bristles, are preserved in the underlying sediments, their fossil record is relatively well known, with the oldest stomatocysts found in Early Cretaceous sediments. Fossil stomatocysts have proven very useful in palaeolimnological studies, particularly when reconstructing past nutrient levels, whereas their marine counterparts are a proxy for past sea‐ice distribution. Key Concepts: Genetic studies have shown that the Chrysophyceae sensu stricto and Synurophyceae are closely related, whereas the other taxa previously included in the Chrysophyceae sensu lato belong to different algal classes. Chrysophytes and synurophytes are heterokont algae, with a long ‘flimmer’ flagellum and a short ‘whiplash’ flagellum and with flagellar swellings on one or both flagella. Fucoxanthin is the main pigment responsible for their ‘golden brown’ colouration. Cells may possess silicified scales (but only synurophytes have bristles) produced by Golgi‐derived vesicles. Scale and bristle morphology appears to be species‐specific and is thus a key criterion in the identification of the taxa. Silicified resting stages bearing a plugged pore (stomatocysts) are unique to the Chrysophyceae and Synurophyceae, and may also be species‐specific. Stomatocysts are often preserved in the underlying sediments, and have been used as palaeoenvironmental indicators. The oldest stomatocysts were found in Early Cretaceous marine sediments from the Southern Ocean, whereas the oldest silicified scales and bristles were found in Middle Eocene freshwater sediments from northwest Canada.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,001 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».