Taphonomy of lacustrine shoreline fish-part conglomerates in the Late Triassic age Lockatong Formation (Collegeville, Pennsylvania, USA): Toward the recognition of catastrophic fish kills in the rock record H. Fitzgerald Malenda a , Edward L. Simpson a, ⁎, Michael J. Szajna b , David L. Fillmore a , Brian W. Hartline c , Elizabeth A. Heness a , Erin R. Kraal a , Jewels L. Wilk a a Department of Physical Sciences, Kutztown University of Pennsylvania, Kutztown, PA 19530, USA b State Museum of Pennsylvania, Harrisburg, PA 17120, USA c Reading Public Museum, 500 Museum Road, Reading, PA 19611, USA abstract article info Article history: Received 18 July 2011 Received in revised form 23 November 2011 Accepted 25 November 2011 Available online 4 December 2011 Keywords: Triassic Fish taphonomy Lockatong Formation Newark basin Fish parts, bones and scale elements, preserved in sandstones and conglomerates characterize an uncommon type of lacustrine strandline setting identified in the Triassic Lockatong Formation of the Newark Supergroup. The Triassic fish-part sandstones and conglomerates are composed of disarticulated skeletal remains and formed during the lake expansion phase. Diverse mudstone-clast types derived from the underlying low- stand playa deposits integrated into the younger transgressive shoreline sequence that contains disarticu- lated fish parts. We propose that the Salton Sea, California, USA is a modern hypersaline lacustrine environmental analog for the deposition of fish remains. On the Salton Sea, high-wind events cause mass fish kills forming a modern shoreline dominated by barnacles and fish remains. Using modern day observa- tions from fish kills in the Salton Sea, California, USA, we suggest that the following taphonomic scenario: mass kills of Triassic fish species took place during deposition of the lacustrine Lockatong Formation. High wind events caused overturning of the lake waters either depleting oxygen or toxically poisoning the fish. After death, bacterial decomposition bloated the fish by generated gas in tissues causing the fish carcasses to float. The decomposing fish carcasses were driven shoreward by wind and wave action and deposited on the shoreline and possibly scavenged by phytosaurs. Following soft tissue decay, the disarticulated re- mains were reworked into normally graded beds composed of intraclasts and fish-part elements. The inter- mixing of intraformational clasts and fish parts reflects the impact of storms on the lacustrine shoreline during the expansion phase of the Van Houten cycle, short period Milankovich frequency cycles that consist of three recorded phases of lake rise to fall recorded in various facies stackings. © 2011 Elsevier B.V. All rights reserved. 1. Introduction Thick accumulations of disarticulated fish debris are unusual in the rock record (Ferber and Wells, 1995; Mancuso, 2003). Previous studies have mainly focused on the action of predators in disarticulat- ing fish carcasses (Wilson, 1987). Normally graded beds of disarticu- lated fish debris concentrated by shoreline/shoreface sedimentation processes discovered in the Lockatong Formation opens a new win- dow into the taphonomic preservation of fish within the Newark basin strata and possibly other lacustrine sequences. The Triassic–Jurassic Newark basin of eastern USA is one of the best-studied rift-fill sequences formed from the initial break up of Pangea (Fig. 1; Smoot and Olsen, 1985, 1988, 1994; Schlische and Olsen, 1990; Smoot, 1991; Olsen et al., 1996). Newark basin strata contain a wealth of vertebrate fossils, including numerous complete to near-complete articulated fish fossils from deep-water, chemically stratified-lake deposits (McCune et al., 1984; McCune, 1986; Olsen, 1988; Smoot and Olsen, 1994; McCune, 1996, 2004; Whiteside et al., 2011). Systematic, detailed examination and collection of these well-preserved fish fossils in the Newark basin provided infor- mation concerning a variety of fish groups, including semionotids, coelacanths, redfieldiids, and holosteans. Important insights from these fossils include the recognition of species flocks, timing of rapid speciation events, species endemism, atavism, and rapid fluctu- ations in species diversity linked to specific parts of lacustrine lake- level cycles (see McCune et al., 1984; McCune, 1986, 1987a, 1987b, 1990, 1996, 2004; Olsen and McCune, 1991; Whiteside et al., 2011). The shoreface of the Salton Sea, California, USA provides a modern day analog for the accumulation of disarticulated fish debris observed in the Newark basin (Britton, 1988; Berry and Anderson, 2010) In the Salton Sea there is a strong correlation between strong winds that overturn the stratified lake waters causing significant fish and Palaeogeography, Palaeoclimatology, Palaeoecology 313-314 (2012) 234–245 ⁎ Corresponding author. Tel.: + 1 610 683 4445. E-mail address: simpson@kutztown.edu (E.L. Simpson). 0031-0182/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.palaeo.2011.11.022 Contents lists available at SciVerse ScienceDirect Palaeogeography, Palaeoclimatology, Palaeoecology journal homepage: www.elsevier.com/locate/palaeo