Skip to Main Content
GEOREF RECORD

A dinosaur tracksite in an early Liassic tidal flat in northern Italy; paleoenvironmental reconstruction from sedimentology and geochemistry

Marco Avanzini, Silvia Frisia, Koenraad van den Driessche and Eddy Keppens
A dinosaur tracksite in an early Liassic tidal flat in northern Italy; paleoenvironmental reconstruction from sedimentology and geochemistry
Palaios (December 1997) 12 (6): 538-551

Abstract

Lateral and vertical sedimentological, ichnological, and geochemical characteristics of a tracksite at Lavini di Marco (Southern Alps, Northern Italy) allowed for the reconstruction of a semi-arid, coastal, life-sustaining environment for sauropods and theropods that lived in the western margin of tropical Pangaea at the Triassic-Jurassic transition. Isotopic analyses reveal that there was little influence of meteoric water in the diagenetic transformation of trampled sediments. Consequently, freshwater lenses were probably ephemeral, but could still sustain some vegetation and support animal life. The environment was dominated by the presence of marine waters in sediment pores. Intense evaporation caused partial dolomitization in the morphologically "low lying" parts of the site by modified marine waters. Dolomite precipitation favored the preservation, via early cementation, of dinosaur footprints by carbonates and, possibly, other soluble minerals. Early cementation in semiarid and arid settings could play a major role in the fossilization of dinosaur footprints on carbonate tidal flats. Dinosaur footprints provide unequivocal proof of subaerial exposure of the platform, which has important consequences for both cyclo- and sequence stratigraphic studies. Commonly, bed surfaces in Alpine outcrops are scarce and paleontologic studies have had to rely upon vertical outcrop faces. In this case, the recognition of dinoturbation structures becomes very important. At Lavini we had the opportunity to study the same footprints both on the bedding surface and in bed cross-section. Here we provide detailed descriptions of dinoturbation structures that should aid in the recognition of subaerial exposure surfaces in Mesozoic tidal flats. The preserved footprints at Lavini indicate that fossilization of ichnofaunas is possible in a variety of subenvironments within a tidal flat, in a general inter-supratidal setting characterized by alternating periods of seawater influx and dryness.


ISSN: 0883-1351
Serial Title: Palaios
Serial Volume: 12
Serial Issue: 6
Title: A dinosaur tracksite in an early Liassic tidal flat in northern Italy; paleoenvironmental reconstruction from sedimentology and geochemistry
Affiliation: Museo Tridentino di Scienze Naturali, Trent, Italy
Pages: 538-551
Published: 199712
Text Language: English
Publisher: Society of Economic Paleontologists and Mineralogists, Tulsa, OK, United States
References: 60
Accession Number: 1998-023978
Categories: StratigraphyVertebrate paleontologySedimentary petrology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. strat. col., geol. sketch map
N36°30'00" - N47°30'00", E06°30'00" - E19°00'00"
Secondary Affiliation: Vrijie Universiteit Brussels, BEL, Belgium
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data supplied by SEPM (Society for Sedimentary Geology), Tulsa, OK, United States
Update Code: 199809
Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal