PROBLEMATIC SPECIES: COLOR PROBLEMATIC SPECIES: COLOR PATTERNS REVEALED BY UV PATTERNS REVEALED BY UV LIGHT AS A CHARACTER FOR LIGHT AS A CHARACTER FOR SYSTEMATICS IN MOLLUSC SYSTEMATICS IN MOLLUSC

FOSSILSFOSSILS

– AN EXAMPLE FROM THE HELLENIC REGION –

NATIONAL AND KAPODISTRIAN UNIVERSITY OF ATHENSFACULTY OF GEOLOGY & GEO-ENVIRONMENT DEPARTMENT OF HISTORICAL GEOLOGY & PALEONTOLOGY

Study Area : Rhodes

Geological Setting: Faliraki section, Rhodes

The Glycymeris genus• Paralic environment • Symmetrical valves• Isomyarian• Straight umbo• Taxodont teeth

Problems with identification and characterization of species

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)

Greek fossils of Glycymeris

Glycymeris cor Glycymeris glycymeris

Mediterranean Glycymeris species

Glycymeris glycymeris

Glycymeris bimaculata Glycymeris violascens

UV light : the method

Photo by Caze, 2010

• 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

• 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

UV light : the method

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

UV Light

Photo of G. violascens under UV light Schematic shape of the color pattern of G. violascens

CONCLUSIONS

• Fast retrieval of 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

Thank you for your attention!