N. Jb. Geol. Paläont. Abh. 267/1, 117–124 Article Published online December 2012 A Speiballen from the Lower Jurassic Posidonia Shale of South Germany Detlev Thies and Rolf Bernhard Hauff with 1 figure Thies, D. & hauff, R.B. (2013): A Speiballen from the Lower Jurassic Posidonia Shale of South Ger- many. – N. Jb. Geol. Paläont. Abh., 267: 117–124; Stuttgart. Abstract: A Speiballen (regurgitated compacted mass of indigestible stomach contents) from the Lower Jurassic Posidonia Shale of Ohmden, South Germany contains remains of four specimens of the actinopterygian Dapedium sp., the specific identity of which remains obscure, and a lower jaw of a specimen identified as Lepidotes sp. A list of five suitable characters is proposed to distinguish fossil Speiballen containing specimens from other vertebrate fossils. Large, potentially piscivorous animals in the Posidonia Shale ecosystem comprise chondrichthyans (Hybodus), other actinoptery- gians (pachycormiforms) and marine reptiles (crocodilians, ichthyosaurs, plesiosaurs). Only juvenile ichthyosaurs (Stenopterygius) are known to have preyed on Dapedium. Available data are, however, insufficient to clearly identify the Speiballen producer. The heavy scale armour of basal neoptery- gians such as Dapedium undoubtedly hampered digestion of these fishes and in this way provided additional protection against predators. Key words: Jurassic, Fossillagerstätte, Holzmaden, ecosytem, predation. 1. Introduction English equivalent of the German term ‘Speiballen’ (or ‘Gewölle’, which means the same) does not seem to Speiballen are understood to be regurgitated com- exist. Burrow & Turner (2010) described an assem- pacted masses of indigestible stomach contents. They blage of skeletal element, tooth whorls and scales of are released in the form of gastric pellets through the the acanthodian Nostolepis scotica from the Early De- pharynx in contrast to faeces that represent intestinal vonian of Scotland comparable in terms of taphonomy contents that are excreted through the anus. Speibal- and preservation to the Dapedium specimens 2 and 3 len mostly contain indigestible remains of organisms in our fossil as a regurgitate, however, without giving caught and eaten by predators, such as bones, fur or reasons for their view. PollarD (1990) used the term feathers left over in the crop or stomach after other ‘regurgitates’ for some Carboniferous shell debris softer components of a prey are macerated and digest- probably produced by sharks. As to the diet of a Lower ed. In the fossil record they form together with copro- Jurassic ichthyosaur from Lyme Regis, England, he lites and fossilised intestinal fillings a useful source mentioned that only the head and arms of belemnites of information on the diets of fossil animals and can were eaten whereas the bodies and rostra were bitten thus be used to reconstruct food chains. A precise off and ‘regurgitated’ (and not swallowed). In ‘Collins ©2012 E. Schweizerbart’sche Verlagsbuchhandlung, Stuttgart, Germany www.schweizerbart.de DOI: 10.1127/0077-7749/2012/0301 0077-7749/2012/0301 $ 2.00 118 D. Thies and R.B. Hauff English Dictionary–Complete and Unabridged’ (www. by a large ichthyosaur, or a marine crocodile, as pro- thefreedictionary.com/regurgitates; accessed 20 July posed by ernsT in 1967. The indigestible bony remains 2012) the term ‘regurgitate’ is defined in the zoologi- of the little dinosaur were finally regurgitated by the cal sense as ‘to bring back to the mouth (undigested scavenger and preserved as a Speiballen. Otherwise or partly digested food with which to feed the young)’ Speiballen seem to be unknown from the Posidonia (occurring in some birds and certain other animals). Shale. The specimen described below appears there- Thus, the English term ‘regurgitate/s’ is ambiguous. fore to be the fourth record of a Speiballen reported Therefore, and because the translation ‘regurgitated from the Posidonia Shale. [M. Maisch (pers. comm.) gastric pellet’ for ‘Speiballen’ is a little unwieldy we considers that it is possible that Speiballen occur more prefer here to use the German term for the fossil stud- frequently in the Posidonia Shale than is evident from ied below. the literature, and that their rareness is only affected Vertebrate Speiballen are well known from several by collecting and description biases.] groups of Recent birds such as owls, birds of prey or seagulls, and from carnivorous mammals such as cats. 2. How to recognise a fossil vertebrate Yielding information on the food sources of the birds Speiballen or mammals concerned they are helpful in recognizing food chains and webs. Among Recent reptiles Speibal- Speiballen of Recent owls can easily be identified by len are known from crocodiles (scherPner 1980) and the presence of felted masses of hairs (which led to from egg-eating snakes (Dasypeltinae), which regur- aBel (1935) defining the German term ‘Gewölle’) gitate broken eggshell remains (reinharD & Vogel containing disarticulated skeletal elements and teeth 1980). Fossil Speiballen appear to be rare in the Juras- of small mammals on which the birds preyed. In fossil sic (Janicke 1969; BarThel & Janicke 1970). Janicke Speiballen of owls from the glacial epoch preserved (1970) and BarThel (1978) described fossil remains in caves in Austria the hairs were decomposed leav- of the actinopterygian Caturus (synonymous Strobi- ing only layered accumulations of small disarticulated lodus) from the Solnhofen Plattenkalk (Late Jurassic, bones and teeth of prey. The nature of these bone ac- Tithonian) and interpreted it as a Speiballen produced cumulations as Speiballen remains was revealed by by a large fish or crocodile. DieTl & schweigerT associated Recent Speiballen because the caves were (2001) reported a Speiballen from the Nusplinger Plat- occupied by owls continously since the Ice Age (aBel tenkalke (Late Jurassic, Kimmeridgian) mainly com- 1935). posed of bones of the pterosaur Rhamphorhynchus. Vertebrate fossils older than the glacial epoch can- The pterosaur is assumed to have been caught alive not be as easily identified as Speiballen. From obser- or scavenged by an adequately large predator such as vations on vertebrate fossils previously interpreted as Caturus or the crocodilians Geosaurus or Dakosau- Speiballen by Burrow & Turner (2010), ernsT (1967), rus. keller (1977) considered a coiled-up skeleton of Jäger (2001), Janicke (1970), Janicke & schairer an 1.6 m long specimen of the ichthyosaur Stenopter- (1970), and keller (1977), the following list of charac- ygius quadriscissus from the Lower Jurassic Posidonia ters can be derived by which fossil vertebrate Speibal- Shale of South Germany as a Speiballen regurgitated len may be diagnosed: by another large predatory ichthyosaur, Temnodonto- 1. Speiballen may contain skeletal remains of one or saurus (synonymous Leptopterygius). Another ran- several closely packed individuals of one or more domly arranged and compacted pile of disarticulated species; bones of a small ichthyosaur from the Posidonia Shale 2. the skeleton/s of the individual/s are disarticulated in South Germany was also suspected by Jäger (2001) to a varying degree; to be a Speiballen produced by a Temnodontosaurus. 3. skeletal elements are closely packed and in disor- A similar explanation might apply to the assemblage der, not being in accordance with their natural ar- of disarticulated skeletal elements including the skull rangement; of a small ornithischian dinosaur found in a concre- 4. the vertebral column if still intact is extremely tion within the Posidonia Shale in North Germany and coiled up; described by hauBolD (1990) as Emausaurus ernsti. 5. the bony remains of a vertebrate Speiballen of- Since dinosaurs were land-bound, in this case a river ten include the skull or skeletal elements thereof might have washed the carcass of a small, juvenile di- (whenever the prey was swallowed whole by the nosaur into the Posidonia Shale sea where it was eaten predator). Drifting marine vertebrate carcasses A Speiballen from the Lower Jurassic Posidonia Shale of South Germany 119 loose their limbs and skulls while drifting; head, against each other and the left mandible now reveals the os- limbs and trunk of such carcass can then be em- sification pattern of the medial side of the lower jaw. The specimen measures approx. 18 cm in standard length and 11 bedded in the sediment at different places (schäfer cm in maximum dorso-ventral height. 1972). Specimen 2 of Dapedium also shows its right side but is less well preserved and posteriorly covered by specimens 1 Fossil vertebrate Speiballen may not show all of these and 3. Apart from the ventralmost portion the scale armour characters in the same fossil. For example, the coiled- has disintegrated. The cleithrum pierces out of the Speibal- up specimen of the ichthyosaur Stenopterygius quad- len like a curved spine. The caudal part of the dermal skull (frontal, parietal, dermopterotic) is still present but other riscissus from the Lower Jurassic Posidonia Shale of bones such as the nasal and the lower jaw seem to have gone Holzmaden, considered to be a Speiballen by keller or may be hidden underneath other skeletal remains. (1977), agrees with all five characters listed above. By Dapedium specimen 3 is even more disintegrated and contrast, an accumulation of six coiled-up vertebral largely covered by specimen 1. Some cephalic ossifications columns of the actinopterygian Leptolepis sprattifor- are preserved. They are, however, broken into pieces and do not allow