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Problematic species: color patterns revealed by UV light as a character for systematics in mollusc fossils - an example from the Hellenic region. Koskeridou E., Thivaiou D.
This document summarizes a study examining the use of ultraviolet (UV) light to reveal color patterns in mollusc fossils from Rhodes, Greece as a tool for systematics. The study focused on fossils from the Glycymeris genus found at the Faliraki section of Rhodes. Under UV light, the fossils displayed distinct color patterns that could differentiate similar Glycymeris species. This non-destructive method provides a new systematic character for identifying fossil mollusc species based on their residual UV-revealed color patterns.
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Problematic species: color patterns revealed by UV light as a character for systematics in mollusc fossils - an example from the Hellenic region. Koskeridou E., Thivaiou D.
- 1. NATIONAL AND KAPODISTRIANUNIVERSITY OF ATHENS FACULTY OF GEOLOGY & GEO-ENVIRONMENT DEPARTMENT OF HISTORICAL GEOLOGY & PALEONTOLOGY PROBLEMATIC SPECIES: COLOR PATTERNS REVEALED BY UV LIGHT AS A CHARACTER FOR SYSTEMATICS IN MOLLUSC FOSSILS – AN EXAMPLE FROM THE HELLENIC REGION –
- 2. Study Area :Rhodes
- 3.
- 4. The Glycymeris genus •Paralic environment • Symmetrical valves • Isomyarian • Straight umbo • Taxodont teeth Problems with identification and characterization of species
- 5. Biometry • Typological descriptions • Shape descriptions length = f (width) for Glycymeris violascens (grey), regression coefficient: R2=0.876; length = f (width) for two fossil species of the Middle Lutetian, Glycymeris pulvinata (orange) and Glycymeris dispar (blue) (regression coefficients: R2(G. pulvinata)=0.949; R2(G.dispar)=0.969)
- 6. Greek fossils ofGlycymeris Glycymeris cor Glycymeris glycymeris
- 7. Mediterranean Glycymeris species Glycymeris glycymeris Glycymeris bimaculata Glycymeris violascens
- 8. UV light :the method • Color patterns have been used for 200 years • UV light method was first described in 1967 • It has been successfully used by Caze (2010) on fossils from the Paris Basin Photo by Caze, 2010
- 9. UV light :the method • First ever application to Greek fossils from Rhodes (good preservation of the specimens) • The specimens have important morphological similarities • Preliminary step: sodium hypochlorite (bleach) bath for the re-oxidation of the residual pigments
- 10. UV Light :Results • Color patterns can differentiate and define similar species Photo of G. dispar under UV light Photo of G. violascens under UV light
- 11. UV Light Photo ofG. violascens under UV light Schematic shape of the color pattern of G. violascens
- 12. CONCLUSIONS • Fast retrievalof results • Non-destructive method • Characterization of the color pattern of the studied species • Residual coloration can be used as a systematic character on fossil species
- 13. Thank you foryour attention!
Editor's Notes
- #4 Large Glycymeris bed + photo from the field
- #5 Common fossil taxon Forms large fossil beds We found it in Rhodes We wanted to see if there was one or more species in the bed because the morphospace of G. violascens is not very well known, for that we used UV light. We also wanted to compare the results to another Glycymeris species in order to have a better idea as far as the validity of the method is concerned.
- #6 The range of sizes for the three species is different, and in order to read the data more easily we present it in two different figures. The descriptor R 2 (varience) shows the differences between the global shapes of the shells, it is very similar for the two lutetian species, but different from g. violascens : illustration of the global difference of the shape of the shells. Τυπολογικές περιγραφές διαστάσεις της θυρίδας. Η παράμετρος R 2 περιγράφει το κάθε είδος, και δείχνει τη διαφορά μεγέθους σε σχέση με το μέσο όρο μεγέθους στη διάρκεια της οντογένεσης. Είναι η διαφορά της κλίσης του άξονα y που μπορεί να δείξει κάποια διαφορά στα σχήματα ειδών του γένους αυτού. Σε αυτή τη περίπτωση όμως δεν βλέπουμε κάτι τέτοιο μιας και τα είδη έχουν πολλές ομοιότητες. Επομένως η βιομετρία δεν είναι μια μέθοδος που μπορεί να βγάλει σαφή και σημαντικά αποτελέσματα.
- #8 Σημερινά είδη glycymeris από τη μεσόγειο, να φαίνονται οι χρωματικές διαφορές τους έντονα θα δείξουμε πως ισχύει το ίδιο πράγμα και στα σημερινά
- #11 Πως χρησιμοποιείται η μέθοδος
- #12 Proposition of a model for characterazing the color patterns of this bivalve genus.
- #13 The fact that this method is non-destructive allows not only to work on collected material but also on collections. Residual coloration on fossils used as it is used on recent species + it is useful to work on species that also have known fossils in order to make sure that the method works.