NMITA:Neogene Marine Biota of Tropical America

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Thysanus navicula (Duncan, 1864)

Holotype: BM(NH) R28766

Morphologic Description:

Meander series sinuosity: straight

Colony size: small (<10cm)

Attachment of skeleton: free-living

Epitheca: absent

Wall development between buds: never

Symmetry of bud geometry: bi-directional

Calice or valley width: large (10-15mm)

Calice relief: low (<2mm)

Calicular platform shape: u-shaped

Coenosteum: absent

Exothecal dissepiments: absent

Number of septal cycles: >3

Septal spacing (per 5mm): 6-12

Relative septa thickness: equal

Relative costae thickness: equal

Septal lobes: absent

Paliform lobes: present

Columella continuity: continuous

Columella width: <=1/4

Endothecal dissepiments: few

Wall structure: parathecal

Double or single wall: single

Distribution:

Late Miocene to Early Pliocene : Gurabo Fm., Rio Cana, Dominican Republic; Gurabo Fm., Rio Cana, Dominican Republic; Gurabo Fm., Rio Gurabo, Dominican Republic; Gurabo Fm., Rio Gurabo, Dominican Republic;

Early Pliocene : Mao Fm., Rio Cana, Dominican Republic; Gurabo Fm., Rio Gurabo, Dominican Republic;

Late Pliocene : Bowden Fm., Bowden Shell Beds, Jamaica; Bowden Fm., Bowden seacliff, Jamaica;

Late Pliocene to Early Pleistocene : 'Old Pera' beds, Pera Point, Jamaica;