Fig 1.
Graphical and anatomical elements characterizing the immature nature of the Strud placoderm material.
(A) length vs. width graph of anterior ventrolateral plates of Phyllolepis undulata from Belgium. (B) length vs. width graph of anterior ventrolateral plates of Phyllolepis undulata from Belgium and Pennsylvania (number of specimens from Pennsylvania non-statistically valid). (C) anterior median dorsal plate of Grossilepis rikiki (IRSNB P.9254). (D) length vs. height graph of median dorsal plates of Turrisaspis elektor from Pennsylvania and T. strudensis from Belgium (number of specimens from Belgium non-statistically valid). The red dashed lines represent assumed limits between immature and adult specimens. (A)-(B) modified from [2], (C) modified from [4], (D) modified from [5].
Fig 2.
Reconstruction of the immature placoderms and diagrammatic model of the Strud nursery.
Immature placoderms (from top to bottom) Turrisaspis strudensis (left lateral view), Grossilepis rikiki (dorsal view), Phyllolepis undulata (dorsal view). Diagrammatic model of the Strud nursery displaying the habitat partitioning: on the left, shallow waters of the nursery with immature placoderms inside and Rhacophyton plant on the bank; on the right, deeper area with the placoderm adults. Scale bars equal 2 cm. Animal and environmental reconstructions by J. Jacquot Haméon (MNHN, Paris).