Fig. 1 in Chaetognath grasping spines from the Upper Mississippian of Arkansas (USA)

Fig. 1. Eoserratosagitta serrata gen. et sp. nov., Cove Creek (Arkansas, USA), Middle Chesterian (Namurian Aequivalent). A. Aconcretion fragment showing part of the accumulation of spines (s), scale bar 0.1 mm. B. A fragment of the middle part of a spine showing the concretion filled central cavity (cc), a row of bullet−like, hollow (now concretion−filled) denticles (d) on the concave side (to the left), and five longitudinal bands (b) separated by fine ribs (r) on the outer surface of the spine wall, scale bar 0.1 mm. C. Close−up of B showing fiber (f) impressions, scale bar 0.01 mm. All SEM micrographs.