Phacopida

Flexicalymene trentonensis

Order Phacopida / Suborder Calymenina / Superfamily Calymenoidea / Family Calymenidae

Katian (Late Ordovician)Canada, USA
Flexicalymene trentonensis — photo 1
Photo 1 · Holotype AMNH-FI-140954 (Canada; Hopkins et al., 2024) Paratype MCZ 111710 (USA; Hopkins et al., 2024) Main differences between F. senaria (A-D) and F. trentonensis (E-H) Literature specimen (Canada; Isotalo 2015) (Hopkins et al., 2024)
Flexicalymene trentonensis — photo 2
Photo 2 · Holotype AMNH-FI-140954 (Canada; Hopkins et al., 2024) Paratype MCZ 111710 (USA; Hopkins et al., 2024) Main differences between F. senaria (A-D) and F. trentonensis (E-H) Literature specimen (Canada; Isotalo 2015) (Hopkins et al., 2024)
Flexicalymene trentonensis — photo 3
Photo 3 · Holotype AMNH-FI-140954 (Canada; Hopkins et al., 2024) Paratype MCZ 111710 (USA; Hopkins et al., 2024) Main differences between F. senaria (A-D) and F. trentonensis (E-H) Literature specimen (Canada; Isotalo 2015) (Hopkins et al., 2024)
Flexicalymene trentonensis — photo 4
Photo 4 · Holotype AMNH-FI-140954 (Canada; Hopkins et al., 2024) Paratype MCZ 111710 (USA; Hopkins et al., 2024) Main differences between F. senaria (A-D) and F. trentonensis (E-H) Literature specimen (Canada; Isotalo 2015) (Hopkins et al., 2024)
Classification
Order Phacopida / Suborder Calymenina / Superfamily Calymenoidea / Family Calymenidae
Genus
Flexicalymene Shirley, 1936
Genus author
Shirley J.
Genus etymology
flex-, Latin, curved; Calymene, a trilobite genus name
Species
F. trentonensis Hopkins & Martin, 2024
Species author
Hopkins M. J. & Martin M. J.
Species etymology
Trenton, Trenton Falls, New York, USA, near the locality, and the Trenton Group, the horizon of the specimens
Age
Katian (Late Ordovician)
Distribution
Canada, USA
Diagnosis
This species is very similar to Flexicalymene senaria, with the following main differences: larger axial nodes, a longitudinally longer anterior border, short genal spines at the genal angles, and a pygidial axis of 7 rings plus a terminal piece, with deeper pleural and interpleural furrows in the pygidial pleural region.
Remarks
This species was long confused with Flexicalymene senaria, and some transitional forms remain to be studied.