Saturday, September 3, 2016

[PaleoIchthyology • 2016] Placoderm Assemblage from the Tetrapod-Bearing Locality of Strud (Belgium, Upper Famennian) Provides Evidence for a Fish Nursery


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). 

Abstract

The placoderm fauna of the upper Famennian tetrapod-bearing locality of Strud, Belgium, includes the antiarch Grossilepis rikiki, the arthrodire groenlandaspidid Turrisaspis strudensis and the phyllolepidid Phyllolepis undulata. Based on morphological and morphometric evidence, the placoderm specimens from Strud are predominantly recognised as immature specimens and this locality as representing a placoderm nursery. The Strud depositional environment corresponds to a channel in an alluvial plain, and the presence of a nursery in such environment could have provided nutrients and protection to the placoderm offspring. This represents one of the earliest pieces of evidence for this sort of habitat partitioning in vertebrate history, with adults living more distantly from the nursery and using the nursery only to spawn or give live birth.

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).


Sébastien Olive, Gaël Clément, Edward B. Daeschler and Vincent Dupret. 2016. Placoderm Assemblage from the Tetrapod-Bearing Locality of Strud (Belgium, Upper Famennian) Provides Evidence for a Fish Nursery. PLoS ONE. 11(8): e0161540.


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