Abstract

Traditionally test morphology has been used to resolve species differentiation in foraminifera. In recent years molecular methods have come into vogue, but are not practical for comparison with fossil specimens.

Test morphology isn’t strictly dictated by genetics, but can be influenced by environmental factors experienced during ontogeny.

Replicate samples of specimens were collected from the Indian River Lagoon’s St. Lucie Inlet on the east coast of Florida.

Measurements

Chamber Number (#CH): Number of chambers including proloculus.

Largest Test Diameter (LTD): Widest test diameter, from final chamber perpendicular to opposite side of test.

*Min. Test Diameter (MTD): Diameter across test from chamber adjacent to final chamber, but not from the penultimate chamber.

Proloculus Largest Diameter (PLD): Largest diameter across proloculus.

Umbilical Plug Number (UP#): Number of plugs, defined as full, separate plugs.

Umbonal Plug Largest Diameter (UPLD): Maxim diameter across umbonal plug if present.

*Area of Umbonal Depression (AUD): Approximated by a best fit circle with points on the folia/chamberlets of chambers.

Coiling Direction (CD): Direction that chambers are added, I’m not sure which side its measured.

Number of Whorls (#W): Approximation of whorls in from first chamber to the final.

**Chambers per Whorl (Ch/Wh): Chambers per whorl, whorls are complete revolutions around from the first chamber after the proloculus.

Test Thickness (TsTh): Maximum thickness of test, measured perpendicular from highest point on side with proloculus to umbonal side.

Penultimate Chamber Angle (PCA): Angle between radial sutures of penultimate chamber, measured on ventral side.

Penultimate Chamber Height (Cn1H): Distance from peripheral side of chamber to inner extent of chamber.

Penultimate Chamber Width (Cn1W): Width of chamber at radial sutures.

*Chamber n Curve (CnC): Curve which approximates periphery of chamber n (Final chamber).

*Chamber n Width (CnW): Width from endpoints of curve.

*Chamber n-1 Curve (Cn1C): Curve which approximates periphery of chamber n-1 (Penultimate chamber).

*Chamber n-2 Curve (Cn2C): Curve which approximates periphery of chamber n-2.

*Chamber n-2 Width (Cn1W): Width from endpoints of curve.

*Final Curve (FC): Curve which approximates periphery of the remainder of the test.

*Number of chambers in Final Curve (#FC): Number of chambers in the final curve approximation. (final whorl -3) *Final Curve Width (FCW): Width from endpoints of final curve approximation.

*Measurements new to this study
**Calculation