INVESTIGADORES
FERNANDEZ Diana Elizabeth
artículos
Título:
Xiphosurid trackways in a Lower Cretaceous tidal flat in Patagonia: Palaeoecological implications and the involvement of microbial mats in trace-fossil preservation
Autor/es:
FERNÁNDEZ, DIANA E.; PAZOS, PABLO J.
Revista:
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2013 vol. 375 p. 16 - 29
ISSN:
0031-0182
Resumen:
Lower Cretaceous trackways assignable to xiphosurids were recently found
in tidally influenced marginal-marine deposits of the Agrio Formation
(Patagonia, Argentina). The aim of this paper is to describe these trace
fossils in detail, discuss their conditions of preservation, make
palaeoecological and taphonomic inferences from them, and analyse the
importance of their palaeogeographic location. These trace fossils are
assigned to Kouphichnium, and five track morphotypes are
established. Microbially induced sedimentary structures (MISS) are
associated with the trackways. Scanning electron microscope (SEM)
studies document the involvement of microbial mats in the preservation
of the trackways by the presence of cyanobacteria-like filament sheaths.
The microbial mats enabled preservation of the tracks by binding and
biostabilisation of the sediment surface. The mostly likely producers of
the trackways are from the subfamily Limulinae. The studied surface
could represent a high-tide mating ground associated with a very shallow
water deposit on a warm Cretaceous tidal flat. These records are the
first convincingly documented trackways produced by xiphosurids in the
Early Cretaceous worldwide and the second fossil record of this group
from the Cretaceous in the Southern Hemisphere.