ORIGINAL PAPER Four-dimensional virtopsy and the taphonomy of a mole from the Oligocene of Lake Enspel (Germany) Bastian Mähler & Achim H. Schwermann & Michael Wuttke & Julia A. Schultz & Thomas Martin Received: 5 June 2014 /Revised: 30 September 2014 /Accepted: 3 December 2014 /Published online: 10 February 2015 # Senckenberg Gesellschaft für Naturforschung and Springer-Verlag Berlin Heidelberg 2015 Abstract A series of actualistic experiments were conducted to reconstruct probable taphonomic scenarios for a fossil mole specimen from the Enspel locality. Extant Talpa europaea carcasses immersed in water initially floated at the water surface then sank after a few hours or remained floating. Soft tissues started to decompose immediately and concomi- tantly putrefaction gas was produced and accumulated inside the body. Consequently, the carcasses became bloated, and the submerged ones re-surfaced. Gas formation and decomposi- tion of soft tissues accelerated with increasing temperature, as expected. The skeletons of primarily floating specimens suc- cessively disarticulated with ongoing decomposition. In mod- erately warm water (19 °C) disarticulation began with the phalanges of the feet, while in warmer water (27 °C), disar- ticulation started with the phalanges of the hands and the lower jaws. Skeletal components of the re-surfaced specimens successively sank until the entire skeleton was disarticulated. Applying these experimental results to a partial skeleton of the Oligocene mole Geotrypus antiquus from Enspel (Germany) suggests that carcass sank whole to the bottom of the lake and did not undergo an extended period of floatation. This inter- pretation is supported by the following characteristics: (1) upper and lower jaws in occlusion, (2) presence of distal hand elements and the left femur and (3) the positions of the elements of the anterior extremities. After decomposition of most or all soft tissues at the bottom of the lake an underwater current from the right side shifted some bones to the left side of the body axis, while the humeri and the still-articulated skull stayed in their original anatomical position. Keywords Geotrypus . Talpa . Micro CT . Decomposition experiments . Mammals . Upper Oligocene . Enspel Introduction The term “virtopsy” was introduced into the field of forensic science by Thali et al. (2003) to designate non- or minimally invasive methods of virtual autopsy using computed tomog- raphy (CT) or magnetic resonance (MR) analysis. Virtopsy provides digital, three-dimensional (3D) insight into a carcass and is additionally used for standard autopsy. We conducted a “4D virtopsy”, a kind of virtual autopsy in which the decom- position process inside a specimen is observed in 3D over time, the fourth dimension. This virtopsy-controlled decom- position method was introduced by Schwermann et al. (2012), but the term “4D virtopsy” is used for the first time in this paper. Various authors have studied and described the decom- position process of mammals in freshwater (e.g. Payne and King 1972; Dodson 1973; Tomberlin and Adler 1998; Hobischak and Anderson 2002; Brand et al. 2003; Chin et al. 2008), but these studies were limited to external obser- vations. Wuttke (1983), Richter (1994), and Richter and Wuttke (2012) documented the decomposition process of small vertebrate carcasses (Anura, Squamata) using 2D X- rays. In 2011, Gill-Frerking and Rosendahl reconstructed a mummified dog from the 16th Century in 3D with the use of CT (Gill-Frerking and Rosendahl 2011). Schwermann and Wuttke ( 2011 ) and Wuttke and Schwermann (2011) presented the results of an actualistic palaeontological experiment on small mammals, in which a This article is a contribution to the special issue “The Fossil-Lagerstätte Enspel – reconstructing the palaeoenvironment with new data on fossils and geology” B. Mähler (*) : A. H. Schwermann : J. A. Schultz : T. Martin Steinmann-Institut für Geologie, Mineralogie und Paläontologie, Universität Bonn, Nußallee 8, 53115 Bonn, Germany e-mail: bastian.maehler@uni-bonn.de M. Wuttke Referat Erdgeschichte, Generaldirektion Kulturelles Erbe RLP, Große Langgasse, 29, 55116 Mainz, Germany Palaeobio Palaeoenv (2015) 95:115–131 DOI 10.1007/s12549-014-0180-x