Manual of Forensic Taphonomy Second Edition Edited by James T. Pokines Ericka N. L’Abbé Steven A. Symes Second edition published 2022 by CRC Press 2 Park Square, Milton Park, Abingdon, Oxon, OX14 4RN and by CRC Press 6000 Broken Sound Parkway NW, Suite 300, Boca Raton, FL 33487-2742 © 2022 selection and editorial matter, James T. Pokines, Ericka N. L’Abbé, and Steven A. Symes; individual chapters, the contributors First edition published by CRC Press 2014 CRC Press is an imprint of Informa UK Limited The right of James T. Pokines, Ericka N. L’Abbé, and Steven A. Symes to be identified as the authors of the editorial material, and of the authors for their individual chapters, has been asserted in accordance with sections 77 and 78 of the Copyright, Designs and Patents Act 1988. All rights reserved. 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British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library Library of Congress Cataloging‑in‑Publication Data Names: Pokines, James T., editor. | Symes, Steve A., editor. | L’Abbé, Ericka N., editor. Title: Manual of forensic taphonomy / edited by James T. Pokines, Steven A. Symes, and Ericka N. L’Abbé. Identifiers: LCCN 2021026484 (print) | LCCN 2021026485 (ebook) | ISBN 9780367774370 (hardback) | ISBN 9780367774592 (paperback) | ISBN 9781003171492 (ebook) Subjects: LCSH: Forensic taphonomy. | Postmortem changes. | Crime scene searches. Classification: LCC RA1063.47 .M36 2022 (print) | LCC RA1063.47 (ebook) | DDC 614/.1—dc23 LC record available at https://lccn.loc.gov/2021026484 LC ebook record available at https://lccn.loc.gov/2021026485 ISBN: 978-0-367-77437-0 (hbk) ISBN: 978-0-367-77459-2 (pbk) ISBN: 978-1-003-17149-2 (ebk) The cover image appears courtesy of Dr. Diane France. DOI: 10.4324/9781003171492 Typeset in Minion by KnowledgeWorks Global Ltd. Contents Editor Biographies xi Contributor Biographies xiii 1 Introduction: The Importance and Use of Forensic Taphonomic Data 1 JAMES T. POKINES 2 Microscopic Destruction of Bone 23 MIRANDA M. E. JANS 3 Soft Tissue Decomposition in Terrestrial Ecosystems 41 ALEXANDRA L. EMMONS, HEATHER DEEL, MARY DAVIS, AND JESSICA L. METCALF 4 Bone Density and Bone Attrition 79 R. LEE LYMAN 5 Effects of Burial Environment on Osseous Remains 103 JAMES T. POKINES AND JOAN E. BAKER 6 Fluvial Taphonomy 163 THOMAS EVANS 7 Marine Environmental Alterations to Bone 193 JAMES T. POKINES AND NICHOLAS D. HIGGS 8 Contemporary Cultural Alterations to Bone: Anatomical, Ritual, and Trophy 251 JOSEPHINE M. YUCHA, ALEXANDRA R. KLALES, ERIC J. BARTELINK, AND JAMES T. POKINES 9 Faunal Dispersal, Reconcentration, and Gnawing Damage to Bone in Terrestrial Environments 295 JAMES T. POKINES vii viii Contents 10 Deposition and Dispersal of Human Remains as a Result of Criminal Acts: Homo sapiens sapiens as a Taphonomic Agent 361 DEREK CONGRAM, ARTHUR GILL GREEN, AND PEARL PEROUZ SEFERIAN 11 Subaerial Weathering and Other Terrestrial Surface Taphonomic Processes 403 JAMES T. POKINES AND CHRISTINE A. SPIEGEL 12 Identifying the Origin of Taphonomic Bone Staining and Color Changes in Forensic Contexts 443 JOHN J. SCHULTZ AND TOSHA L. DUPRAS 13 Taphonomy and the Timing of Bone Fractures in Trauma Analysis 473 ERICKA N. L’ABBÉ, STEVEN A. SYMES, KYRA E. STULL, MARCELLE LaCROIX, AND JAMES T. POKINES 14 Thermal Alteration to Bone 503 ERICKA N. L’ABBÉ, STEVEN A. SYMES, JAMES T. POKINES, TAYLOR YUZWA, DIANA L. MESSER, AMY STROMQUIST, NATALIE KEOUGH, LEANDI LIEBENBERG, AND MARITZA LIEBENBERG 15 DNA Survivability in Skeletal Remains 555 KRISTA E. LATHAM, MEGAN E. MADONNA, AND JENNIFER LAI HIPP 16 Avian Taphonomy 581 JAMES T. POKINES, STEPHANIE EDWARDS BAKER, AND COREY POLLOCK 17 Effects of Recovery Methods 605 JAMES T. POKINES AND JOAN E. BAKER 18 Invertebrate Modification of Bone 631 LUCINDA BACKWELL, JEAN-BERNARD HUCHET, JAMES du GUESCLIN HARRISON, AND FRANCESCO D’ERRICO Contents ix 19 Reptile Taphonomy 667 CARRINGTON S. SCHNEIDER, JAMES T. POKINES, ERICKA N. L’ABBÉ, AND BRIANA POBINER 20 Laws of Taphonomic Relative Timing 695 JAMES T. POKINES 21 Laboratory and Field Methods in Forensic Taphonomy 717 JAMES T. POKINES AND MIRANDA M. E. JANS Index 733 Reptile Taphonomy CARRINGTON S. SCHNEIDER 19 JAMES T. POKINES ERICKA N. L’ABBÉ BRIANA POBINER Contents Introduction and Forensic Relevance 667 Fossil Taphonomic History 669 Crocodilians 670 Crocodilian Species Worldwide 670 Crocodilian Diet and Feeding 670 Digestive Processes 674 Crocodilian Tooth Marks 675 Pits 676 Scores 679 Punctures 680 Crocodilian and Furrows Tooth Mark Patterns 682 Case Study: Nile Crocodile (Crocodylus niloticus) Scavenging in South Africa 685 Other Reptiles 688 Acknowledgements 689 References 690 Your serpent of Egypt is bred now of your mud by the operation of your sun: so is your crocodile. —William Shakespeare Antony and Cleopatra, Act II, Scene 7 Introduction and Forensic Relevance While not as prevalent on bones as the taphonomic effects of carnivores, rodents, and other mammals (see Chapter 9, this volume), reptiles can cause significant alterations to human remains. Crocodilians/crocodylians (i.e., crocodiles, alligators, caimans, and their relatives in the Order Crocodilia) are the extant reptiles with potential to do the most dam- age to bone during initial prey capture and feeding or through scavenging. Whether a crocodilian attack is fatal or not correlates somewhat with the size of the attacking animal and if the intended victim was in the water (Fukuda et al. 2015). Bites, especially from smaller crocodilians, can be minor and survivable (Fukuda et al. 2015; Hertner 2006; Shepherd and Shoff 2014), but traumatic amputation often results from the bites of larger individuals, frequently leading to death quickly or more slowly through later sepsis, with drowning of a secured victim also a common cause (Fukuda et al. 2015; 667 DOI: 10.4324/9781003171492-19 668 Manual of Forensic Taphonomy Haddad and Fonseca 2011; Harding and Wolf 2006; Langley 2005; Wolf and Harding 2014). American alligator (Alligator mississippiensis) bites (including non-fatal attacks) are most often on the extremities but can appear on the head and torso (Langley 2005, 2010). Crocodilian attacks may occur on land or in water, with the latter being much more com- mon (Florida Fish and Wildlife Conservation Commission 2019a; Langley 2010; Sinton and Byard 2016). I instances of attacks by climbing into boats or upon occupants of tents are known (Caldicott et al. 2005; Gruen 2009). Fatal alligator attacks on humans are uncommon in the USA and average one per year, likely due in part to natural mutual avoidance; in comparison, snake bites and vehicle-moose collisions both have an estimated average of six fatalities per year (Conover 2019). Alligator encounters appear to be on the increase, likely caused by the rebound- ing of their populations due to previous endangered species protection (Langley 2005, 2010; Woodward et al. 2019). In Florida, from 1948 (when record keeping began) to 2019, 413 unprovoked alligator bite incidents were recorded, 25 of which were fatal; over the preceding decade, Florida averaged seven unprovoked bites per year that were serious enough to require professional medical treatment (Florida Fish and Wildlife Conservation Commission 2019b). Some attacks may be due to the alligator having been desensitized to human proximity through illegal feeding or discarding food into a body of water populated by alligators (Harding and Wolf 2006; Langley 2010; Wolf and Harding 2014). Harding and Wolf (2006) reported three fatal cases in southwest Florida from alligator attacks and noted six additional cases of postmortem scavenging. In some cases of post- mortem feeding, it is possible that alligators were used as a deliberate method of human body disposal. Attacks by American alligators peak during the warmer months of the year (Langley 2010; Woodward et al. 2019), although this may relate to human activity patterns. Attack rates by Nile crocodiles (Crocodylus niloticus) also vary seasonally; these patterns need to be studied further in order to decrease human fatalities from this source (Pooley 2015, 2016; Pooley et al. 1992). Attacks on humans by other crocodilian species in other parts of the world have been documented and surpass the relative frequency of alligator attacks in the USA. Fatal attacks by Nile crocodiles are common in many countries in Africa (Pooley et al. 1992). Crocodiles are known to kill humans on a regular basis, for example, in southwestern Madagascar along the Mongoky River (Hart and Sussman 2008). Crocodilian attacks are also reported from India (Chattopadhyay et al. 2013) and Brazil (Haddad and Fonseca 2011). In north- ern Australia, fatalities from crocodile attack are not uncommon, with most attributed to the saltwater crocodile (Crocodylus porosus) (Caldicott et al. 2005; Fukuda et al. 2014, 2015; Gruen 2009; Sinton and Byard 2016; Westaway et al. 2011; Wood 2008). These may be expected to increase as this species’s population rebounds. Close to 6000 “problem” saltwater crocodiles had to be relocated from 1977–2013 alone (Fukuda et al. 2014), so the potential for attacks is viewed as significant in this region. The overall amount of trauma caused by saltwater crocodiles, often attaining the larg- est sizes (>5 m) among crocodilians in the world, can be quite severe (Gruen 2009; Mekisic and Wardill 1992; Wood 2008). Davidson and Solomon (1990) examined the remains of a man killed by a saltwater crocodile in Australia. Portions of the body were not consumed, and there was damage including tooth marks on the lower limbs of the individual. The legs of the victim had been torn from the torso and were found 10 meters from the bank of a river. Sinton and Byard (2016) noted that among the 11 saltwater crocodile fatalities they examined, in some cases trauma included the remains being incomplete and highly Reptile Taphonomy 669 fragmented (including recovery of the bulk of remains as stomach contents), crushing/ fracturing of the skull and thorax, avulsion of limbs, and decapitation. Tooth marks were noted in nine of these cases. Fossil Taphonomic History The Order Crocodilia and its antecedents have a long fossil history dating back to the late Permian, over 250 million years ago, and had high diversity by the Mesozoic (Grigg and Kirshner 2015). Species belonging to members of the extant crocodilian families evolved during the Cretaceous and survived the Cretaceous-Paleogene extinction event over 60 million years ago. Crocodilians as we know them today span the entirety of hominin evolution, and their taphonomic effects are relevant to paleontologists as well as foren- sic anthropologists. These species commonly evoke fear due to their status as dangerous predators that frequently come into contact with humans (Pooley 2015, 2016). Some paleontological researchers have detected possible taphonomic effects from crocodilian feeding in the fossil record (Pobiner 2008). A complete turtle skeleton from the Upper Jurassic bears tooth marks along the posterior margin, some of which appear to be healed, that have been attributed to a broad-nosed crocodilian (Joyce 2000). Similar tooth marks on turtle shells from the Upper Jurassic are also attributed to predation by the broad-nosed crocodilian Machimosaurus (Meyer 1994). Botfalvai et al. (2014) found possible crocodilian tooth marks (pits with U-shaped profiles and circular to oval shapes and some associated striations) on a portion of chelonian anterior carapace adjacent to the head on a Late Cretaceous specimen from Hungary. These marks are similar to carni- vore damage to chelonian carapaces from modern environments (Milàn et al. 2010). A spe- cies of crocodilian had similar tooth marks on its skull roof, some of which had a bisected morphology characteristic of modern crocodilians (see “Crocodilian Tooth Marks” section, below). The specimens may have been the prey of an additional crocodilian species known from this fossil locality. Boyd et al. (2013) found evidence of crocodyliform feeding on juvenile ornithischian dinosaur specimens from the Upper Cretaceous in Utah, including a partial tooth crown broken off in one tooth puncture, pits including one bisected mark, and associated hook scores. Noto et al. (2012) also found evidence of crocodilian feeding on chelonian and dinosaur bones from Cretaceous deposits in Texas, including pits (only one potentially bisected), hook scores, and a puncture. Fisher (1981a, b, c) assigned the origin of enamel-less teeth in some Wyoming Paleocene deposits to crocodilian digestion, although crocodile feces did not appear to be the origin of most of the faunal assemblage. Possible traces of crocodilian feeding appear on larger fossil mammal bones at least as far back as the Miocene (Mikuláš et al. 2006). Crocodile feeding has been forwarded as a possible cause of death for multiple early hominin specimens due to their depositional contexts and tooth mark evidence. Davidson and Solomon (1990) noted possible crocodile-inflicted tooth marks to (Olduvai hominin) OH 7, the type specimen for Homo habilis. This damage is consistent with Nile croco- dile, fossils of which have been found at Olduvai (Davidson and Solomon 1990). Crocodile feeding may have been involved in the demise of OH 8 and OH 35, the former of which has extensive tooth markings, including multiple bisected marks (Njau and Blumenschine 2012); the case for crocodile involvement with OH 35 is less clear (Aramendi et al. 2017; Baquedano et al. 2012). Scavenging of hominin remains in cases where crocodile 670 Manual of Forensic Taphonomy involvement is determined is also a plausible scenario. Crocodile tooth marks have also been identified on other Plio-Pleistocene fossils, sometimes appearing similar to hominin butchery marks (e.g., Sahle et al. 2017). Crocodilians Crocodilian Species Worldwide At least 25 species of crocodilians exist in the world today, and their ranges and envi- ronments can be found in Table 19.1 (Alderton 1991; Britton 2012; Grigg and Kirshner 2015; Somma 2021). Of these, two are native to the USA (Figure 19.1): American alligators (Alligator mississippiensis), family Alligatoridae, inhabit the southeastern USA; American crocodiles (Crocodylus acutus), family Crocodylidae, inhabit only the coastal areas of south Florida as well as parts of Central America (National Park Service 2017; US Fish and Wildlife Service 2021). American alligators are found in the wild in Texas, Oklahoma, Arkansas, Louisiana, Mississippi, Alabama, Florida, Georgia, South Carolina, and North Carolina, with the largest populations in Louisiana and Florida (Langley 2005; Somma 2021), and are sometimes kept as pets and/or released outside of this region (Shepherd and Shoff 2014). Spectacled caiman (Caiman crocodilus), an invasive species, has also estab- lished itself in southeastern Florida (Langley 2010; Somma and Fuller 2021). Crocodilians are generally found in tropical regions, but both the American alligator and Chinese alli- gator (Alligator sinensis) are relatively cold-tolerant and are found at the highest elevations and latitudes of any crocodilian species (Grigg and Kirshner 2015). The annual thermal cycle in North America affects the physiology and growth cycle of alligators, which can also affect the number of attacks on humans during a particular time period. In southwest Louisiana, alligators stop feeding in October and do not resume feeding until late March or early April. During the warmer season, captive alligators can grow about 150 cm/year and reach sexual maturity in six years, while wild alligators grow 30 cm/year on average and reach sexual maturity in ten years (National Park Service 2017). Crocodilian Diet and Feeding The diets of crocodilian taxa vary due to factors such as snout shape and body size, the former of which evolved to adapt to different prey types and sizes, and by geographic location, habitat, and prey encountered. American alligators forage opportunistically and exhibit a varied diet, ranging from small insects and crustaceans to large vertebrates. Their prey includes fish, snails, birds, frogs, and mammals that venture near the water’s edge (Grigg and Kirshner 2015; National Park Service 2017). As an American alligator increases in size, its diet becomes more diverse; juveniles tend to prey on invertebrates, whereas large adults prey more on vertebrates than invertebrates (Saalfeld 2010; Wallace and Leslie 2008). While fish are the most prevalent vertebrates in the diet of adult alli- gators, they also prey on terrestrial species. Crocodilians can be surprisingly mobile on land, lunging for short distances to ambush prey out of water and pursuing slower- moving prey (Caldicott et al. 2005). The manner in which crocodilians consume their prey is similar throughout all species and usually follows a sequence of six stages: prey capture, killing, reduction, Reptile Taphonomy 671 Table 19.1 Extant Crocodilian Species by Family Species Binomial Current Range Environments Alligatoridae American alligator Alligator mississippiensis Southeastern USA, Texas though Florida Freshwater (marshes, swamps, and rivers) and sometimes brackish Chinese alligator Alligator sinensis China around the lower Yangtze River Slow-moving freshwater rivers, streams, and ponds Spectacled caiman Caiman crocodilus Central and South America; invasive in southern Florida All lowlands, wetlands, and riverine systems Broad-snouted caiman Caiman latirostris Northern Argentina, Bolivia, southeastern Brazil, Freshwater and brackish mangroves, marshes, Paraguay, Uruguay and swamps Yacare caiman Caiman yacare Northern Argentina, southern Brazil, southern Bolivia, Wetlands, rivers, and lakes Paraguay Black caiman Melanosuchus niger The Amazon basin, including Brazil, Guyana, Peru, and Freshwater riverine systems and other slow- Bolivia moving waters Cuvier’s dwarf caiman Paleosuchus palpebrosus The Amazon basin including Bolivia, Brazil, Colombia, Freshwater forested ravine systems and flooded Ecuador, French Guiana, Guyana, Peru, Surinam, forests around larger lakes Venezuela Smooth-fronted caiman Paleosuchus trigonatus The Amazon basin including Brazil, Bolivia, Colombia, Forest streams Ecuador, French Guiana, Guyana, Peru, Surinam, Venezuela Crocodylidae American crocodile Crocodylus acutus Central and South America; extreme south of Florida Freshwater and brackish coastal habitats Morelet’s crocodile Crocodylus moreletii Belize, Guatemala, Mexico Freshwater swamps and marshes in forested area Cuban crocodile Crocodylus rhombifer Cuba Freshwater swamps, some brackish Orinoco crocodile Crocodylus intermedius The Orinoco basin, Colombia and Venezuela Freshwater riverine systems New Guinea crocodile Crocodylus novaeguineae Papua New Guinea, Irian Jaya Freshwater swamps, lakes, and rivers; rarely coastal Freshwater crocodile Crocodylus johnstoni Northern Australia Freshwater river systems, lakes, and swamps; some brackish (Continued) 672 Manual of Forensic Taphonomy Table 19.1 (Continued) Extant Crocodilian Species by Family Species Binomial Current Range Environments Saltwater crocodile Crocodylus porosus Coastal areas from southern India to northern Australia, Brackish waters around coastal areas and inland including SE Asia, Borneo, Myanmar, Indonesia, and along rivers; can travel in ocean Papua New Guinea Philippine crocodile Crocodylus mindorensis Philippines Freshwater lakes, ponds, and marshes Siamese crocodile Crocodylus siamensis SE Asia and into Indonesia, much reduced from former Slow-moving freshwater swamps, lakes, and range marshes Mugger crocodile Crocodylus palustris Indian subcontinent and adjacent Freshwater lakes, rivers, and marshes; artificial bodies of water Slender-snouted crocodile Mecistops cataphractus Western Africa including the Congo basin and north Riverine habitats with dense vegetation cover, some brackish Nile crocodile Crocodylus niloticus Most of east and southern Africa and Madagascar, Lakes, rivers, freshwater swamps, and brackish excluding north Africa, Sahara, and horn water; seawater-tolerant West African Nile Crocodylus suchus (formerly Western to central Africa Lakes, rivers, freshwater swamps, and brackish crocodile subspecies of C. niloticus) water; seawater-tolerant Dwarf crocodile Osteolaemus tetraspis Western Africa Permanent pools in swamps and areas of slow-moving freshwater in rain forests Congo dwarf crocodile Osteolaemus osborni Congo Permanent pools in swamps and areas of slow-moving freshwater in rain forests Gavialidae Gharial Gavialis gangeticus Northern Indian subcontinent and adjacent Riverine systems, slower pools False gharial Tomistoma schlegelii Indonesia, Malaysia, and Sarawak Freshwater lakes, rivers, and swamps Source: Alderton (1991), Britton (2012), and Grigg and Kirshner (2015). Reptile Taphonomy 673 Figure 19.1 Range of American alligator (Alligator mississippiensis) and the US portion of the range of American crocodile (Crocodylus acutus), overlapping in southern Florida. Southeastern Florida also has an established population of spectacled caiman (Caiman crocodilus) (not shown) overlapping with the two native species. (Data from Somma 2021, Somma and Fuller 2021, and US Fish and Wildlife Service 2021.) defleshing, swallowing, and carcass abandonment (Cleuren and De Vree 2000; Njau and Blumenschine 2006). Crocodilians secure prey through the anterior portion of the jaws and rotate the head sideways so that the angle of approach brings one side of the jaws into contact with the prey. Small animals are repositioned in the mouth of a crocodilian in such a way that one powerful killing bite can be performed. The repositioning of the prey indicates inertial feeding behavior, a stereotypic form of prey transport which is utilized to move large food items from the jaw tips into and through the oral cavity. The head and neck are elevated, and the hyolingual apparatus presses the prey into the mouth. The expansive opening of the jaws draws the prey farther into the mouth cavity (Biknevicius and Ruff 1992; Njau and Blumenschine 2006). These bites can occur multiple times until the prey is killed or crushed. If the prey is larger, further effort is required from the crocodilian. Repositioning the jaws is used to achieve a better grasp on the prey, and bringing the prey underwater can lead to drowning. “Death roll” behavior is common for crocodilians. It entails securing a portion of the prey in its jaws and initiating a violent rotation along the long axis of its body (Chattopadhyay et al. 2013; Drumheller and Brochu 2014; Grigg and Kirshner 2015; National Park Service 2017). Limbs are folded against the body, and the movement is accomplished through motions of the head, trunk, and tail (Fish et al. 2007). Further bites are utilized to transport food into the throat once smaller prey is dead. For larger prey, crocodilians may require additional reduction before swallowing. Though the conical teeth of crocodilians are important for grasping prey, they are not well adapted to cut or tear into soft tissue. Lateral thrashing has been observed in crocodilians as a means to tear smaller portions off of a prey item (Drumheller and Brochu 2014), similar 674 Manual of Forensic Taphonomy Figure 19.2 Nile crocodiles (Crocodylus niloticus) feeding on a Cape buffalo (Syncerus caffer) in the Kruger National Park, South Africa. to shark feeding behavior (Chapter 7). Large prey reduction and defleshing can continue until an entire carcass is consumed (Figure 19.2). Dismemberment can disperse elements, which are then discarded and abandoned (Davidson and Solomon 1990; Wood 2008). For example, turtle shell remnants are often abandoned once the majority of soft tissues have been consumed (Milàn et al. 2010). The bite force of crocodilians can be very high and has been measured at over three times stronger than that of the avid bone-crushing spotted hyena, Crocuta crocuta (Erickson et al. 2012; Chapter 9). Crocodilian bite force also has been shown to scale lin- early with animal size (Erickson et al. 2004; 2012). Erickson et al. (2004) found that captive American alligators bite more forcefully than their wild counterparts due to their larger size, broader heads, shortened jaws, and greater body mass, so bite mark studies on captive specimens can be problematic. This high bite force attained, combined with the dentition of crocodilians, is sufficient to cause a wide variety of bone damage (see below). Digestive Processes Since crocodilians gulp their food in large pieces, their digestive system is complex. Diefenbach (1975a, b) observed the rate of gastric function of spectacled caiman (Caiman crocodilus) relative to temperature. Sixteen small, medium, and large caimans were used. The animals were fed at 15°C, 20°C, 25°C, and 30°C (Diefenbach 1975a). It took four to five days for the caimans to digest their food completely at 30°C, but at 15°C it took more than fourteen days. The digestive system of crocodilians, including American alligators, is highly acidic. Fisher (1981a) conducted feeding experiments that involved four individuals each of American alligator and spectacled caiman that were fed rats and mice. He found that teeth recovered from feces were usually isolated and enamel-less due to decalcification. Features of bones were subdued and more difficult to recognize. Preserved organic matri- ces sometimes retained their histologic structure, though signs of bacterial decomposition Reptile Taphonomy 675 may have begun to show (Fisher 1981a). Wood (2008) reported human remains that were recovered from a saltwater crocodile’s stomach 25 days after the fatal attack occurred. The articular ends of the long bones had been destroyed, and their shafts had extensive thin- ning, with some softening and curling. The bones could still be identified as human from their gross morphology. Keratinized tissues (nails, hair, etc.) survived the digestion process more robustly than cortical bone. Crocodilian Tooth Marks Multiple actualistic studies of crocodilian bone-modifying behaviors and their diagnos- tic traces have been conducted (e.g., Baquedano et al. 2012, Delaney-Rivera et al. 2009, Milàn et al. 2010; Njau and Blumenschine 2006; Njau and Gilbert 2016; Schneider 2018; Westaway et al. 2011). Many marks produced by crocodiles are individually indistinguish- able from mammalian carnivores, but some crocodilian marks are more diagnostic, and the overall damage patterns differ. (See Table 19.2 for a summary of crocodilian tooth marks and Chapter 9 for mammalian tooth mark terminology.) Alligators have 74 to 80 teeth in their mouth at a time, and as the teeth wear down, they are replaced, typically by larger teeth as the individual ages (Enax et al. 2013; Njau and Blumenschine 2006; Poole 1961). An alligator can go through 3000 teeth in a life- time (National Park Service 2017); Poole (1961) estimated that a large, adult Nile croco- dile would have replaced each tooth 45 times. Crocodilian tooth shape also affects the type of marks that they leave on bone. While terrestrial mammalian carnivores have dis- tinctly heterodont teeth adapted to different functions, those of crocodilians are relatively homodont (uniform). There are some differences among their teeth, which show a gradual change in form from anterior (sharper, caniniform) to posterior (more rounded, molari- form) (D’Amore et al. 2019). The size of teeth also varies upon location in the mouth and by species, and the carinae (sharp ridges on conical teeth; Figure 19.3) are more prominent and sharper on the anterior teeth (Poole 1961). When a recently erupted, unworn tooth is involved in a bite, the carinae may leave a “bisected” mark (Drumheller and Brochu 2014). Some pits caused by crocodilians are partly or entirely bisected by a sharp linear depression that can exceed the diameter of the pit, resulting in a V-shaped cross-section. This type of tooth mark has not been identified in any mammalian group and is considered to be potentially diagnostic for crocodilians. Crocodilian tooth marks can occur anywhere on any bone, though the marks are commonly observed on remains that have been stripped of soft tissue. Most affected bones from crocodile-modified assemblages typically have only one or a few tooth marks visible (see “Case Study” section, below). Without context, however, isolated crocodilian modifications are frequently indistinguishable from those made by other agents (Njau and Gilbert 2016; Sala et al. 2014; Sala and Arsuaga 2013). Tooth marks and other damage may occur to bone during all stages of feeding and may be found on bones that were abandoned after feeding (Njau and Blumenschine 2006). Edge polish is characteristic of mammalian carnivores (Chapter 9) and not observed on crocodilian tooth mark morphology. Though bones are typically ingested, crocodilians do not seek out bone marrow as a source of nutrition and therefore do not produce tooth marks while specifically gnawing in order to access the stored fat reserves from the epiphyses as mammalian carnivores do. 676 Manual of Forensic Taphonomy Table 19.2 Tooth Mark Morphology Comparison Between Mammalian Carnivores and Crocodilians Tooth Mark Mammalian Carnivores Crocodilians (see Chapter 9) Pits Circular to angular and range Circular to angular depressions that do not from around 1.5–4.0 mm. penetrate cortical bone. Some pits are bisected by Internal surface crushed; can be a sharp linear depression. Pit diameters can range isolated or associated with other from 0.1–6.0 mm or more. Associated with tooth marks. crushing, grasping, and holding between teeth. Scores/Striations Linear, may angle from a well- Linear impressions in bone ranging from defined pit, and lengths range superficial to deep that do not penetrate cortical from 3.0–13.0 mm. U-shaped bone. May be described as drag-snags and hook cross sections, and variable scores. “Drag-snag” describes a patterned mark orientation to long bone axis, with a pit and associated striae. Associated with though tending towards torsional forces applied against incompletely transverse. Internal surface gripped bones that slip on clasped jaws. Hook crushed; can be isolated or scores are L or J-shaped. Hook scores may associated with other tooth contain internal parallel and sub-parallel marks. striations within the mark. Lengths range from 3.5–55.0 mm. Punctures Circular to oval, semicircular Circular to oval and can penetrate through notches at fracture edges and thick cortical bone. Serial puncturing may be diameter ranges from 2.0–7.5 observed. May be associated with chipping mm. Bowl-shaped cross sections. and shallow to deep cracks that run along the Usually occur on cancellous bone, long axis of bone. Bisected punctures are with thin cortical bone depressed sometimes observed. Diameters range from into trabeculae. 1.0–11.0 mm. Furrows Linear with average length from Furrows occasionally observed in American 13.0–24.0 mm. U-shaped crossed alligator assemblages. Linear tooth marks sections, usually perpendicular to that may penetrate as deep as punctures break edges. Usually occur on though furrows are longer in length than cancellous bone. width. Fracturing Can produce spiral breaks of long Sometimes noted. American alligators can cause bone shafts, and fracture thin, spiral fractures in bones due to their aggressive flat portions of bones. style of feeding. Source: Domínguez-Rodrigo and Piqueras (2003), Njau and Blumenschine (2006), Njau and Gilbert (2016), Schneider (2018), and Selvaggio and Wilder (2001). Pits Tooth pits (Figures 19.4 and 19.5) are rounded or jagged depressions in cortical bone that do not penetrate through it. All types of pits are associated with crushing, grasping, and holding between teeth. Rounded pits are often left behind due to teeth imposing extreme compressive force, and jagged pits typically lack morphology that can be related to tooth position (Njau and Gilbert 2016). As noted above, anterior crocodile teeth tend to leave partly or entirely bisected pits, in which the bisection is a sharp linear depression that may exceed the diameter of the main pit, resulting in a V-shaped cross section (Figures 19.5 and 19.6). Posterior teeth are more frequently worn down and leave more rounded pits (Njau and Gilbert 2016). The diameters of all pits typically range from 0.1 mm to over 6.0 mm (Njau and Blumenschine 2006), and the diameters of bisected pits typically range from 1.4–4.0 mm (Domínguez-Rodrigo and Piqueras 2003; Njau and Blumenschine 2006). Reptile Taphonomy 677 Figure 19.3 Tooth of American alligator (Alligator mississippiensis) showing carinae (ridges), which may leave distinctive marks in bone. Figure 19.4 Pits on the diaphysis of white-tailed deer (Odocoileus virginianus) femur caused by American alligator (Alligator mississippiensis) feeding (Schneider 2018). Note the V-shaped bisections (arrows), diagnostic of crocodilians and not found among mammalian carnivores. The scale is in cm. 678 Manual of Forensic Taphonomy Figure 19.5 Scores (arrows) amid an area of pits on the diaphysis of a white-tailed deer (Odocoileus virginianus) femur caused by American alligator (Alligator mississippiensis) feed- ing (Schneider 2018). Note the bisections and snags on pits and scores on left side and middle; see also Figure 19.4. The scale is in cm. Figure 19.6 Bisected pits (arrows) on white-tailed deer (Odocoileus virginianus) long bone fragment caused by American alligator (Alligator mississippiensis) feeding (Schneider 2018). The scale is in cm. Bisected pits left by Nile crocodiles will usually be observed on long bones and the postcra- nial axial skeleton (Boyd et al. 2013; Brochu et al. 2010; Njau and Blumenschine 2006; Noto et al. 2012; Rivera-Sylva et al. 2009). Striation pivots refer to tooth pits that also indicate a change in direction of the marks due to crocodilian feeding sequence and behaviors. Serial pitting, inflicted by adjacent teeth biting down on bone, occasionally may be observed. Reptile Taphonomy 679 Figure 19.7 Hook scoring (arrow) on a pig (Sus scrofa) femur caused by American alligator (Alligator mississippiensis) feeding (Schneider 2018). The scale is in cm. Scores Scores (striations) are linear impressions in bone ranging from superficial to deep but not penetrating cortical bone (Figure 19.5). Microscopically, striations may have internal striae. Hook scores (Figures 19.7 and 19.8) are a special subcategory that is unique to crocodilian- modified assemblages (Njau and Blumenschine 2006, Njau and Gilbert 2016). Hook scores are L- or J-shaped and created when an impacting tooth changed direction abruptly dur- ing a single biting event (Njau and Blumenschine 2006). Hook scores often contain inter- nal parallel and sub-parallel striations within the main mark. Hook scores typically range from 3.5–55.0 mm in length. The average length for tooth scores produced by mammalian Figure 19.8 Hook scoring (arrow) on a pig (Sus scrofa) femur caused by American alligator (Alligator mississippiensis) feeding (Schneider 2018). Scale is in cm. 680 Manual of Forensic Taphonomy Figure 19.9 Multiple punctures (white arrows) on a pig (Sus scrofa) femoral head caused by American alligator (Alligator mississippiensis) feeding (Schneider 2018). Note hook scoring (black arrow) located distally of the femoral head. The scale is in cm. carnivores is 3.0‒13.0 mm, and mammals have not been noted to produce hook scores (Njau and Blumenschine 2006). The term drag-snag is used to describe similar tooth mark pat- terns to hook scores but which produce deep grooves/striae with an associated pit (Njau and Gilbert 2016). A drag-snag may appear as an elongated pit, with or without internal stria- tions, and may appear with a pivot, creating a wide V-shaped mark with internal striations. Punctures and Furrows Punctures (Figures 19.9 and 19.10) are deeper depressions that penetrate through cortical bone. Punctures may have chipping on the margins and shallow to deep cracks propagat- ing from opposite sides oriented parallel to the long axis of the bone. Punctures observed in crocodilians are sometimes bisected, similar to pits (Domínguez-Rodrigo and Piqueras 2003; Njau and Blumenschine 2006). Bisected punctures are generally not observed in mammalian carnivores. The average diameter of crocodilian punctures is 2.5‒7.5 mm (Domínguez-Rodrigo and Piqueras 2003; Njau and Blumenschine 2006; Selvaggio and Wilder 2001). Sharp-blunt injuries visualized as depressed fractures with (sometimes) V-shaped pits are occasionally observed with puncture defects and are caused by the impact of the crocodile forcefully biting down on bone. If the bone does not collapse due to the force of the bite, a linear radiating fracture can be observed leading away from the impact location (Drumheller and Brochu 2014). Serial puncturing, observed occasion- ally in crocodilian feeding and similar to serial pits, occurs when crocodilians bite down on bone and multiple punctures are inflicted by adjacent teeth (Njau and Blumenschine 2006). Furrows (Figure 19.11) are linear patterns across the bone also with deep penetra- tions through cortical bone, but they are less often observed among crocodilian-created tooth marks than in mammalian carnivore tooth marks (Drumheller and Brochu 2014; Schneider 2018). Furrows are longer in length than width. Reptile Taphonomy 681 Figure 19.10 Serial punctures (black arrow) and a puncture (white arrow) on a pig (Sus scrofa) ilium caused by American alligator (Alligator mississippiensis) feeding (Schneider 2018). Serial tooth marks occur when crocodilians bite down on bone and adjacent teeth impact around sur- rounding area. The scale is in cm. Figure 19.11 Furrows (arrows) on pig (Sus scrofa) pelvis near the acetabulum, caused by American alligator (Alligator mississippiensis) feeding (Schneider 2018). The scale is in cm. 682 Manual of Forensic Taphonomy Crocodilian Tooth Mark Patterns Multiple researchers have examined crocodilian tooth mark patterns experimentally (Table 19.3). Drumheller and Brochu (2014) observed tooth marks of American alligators and compared the results to existing Nile and saltwater crocodile datasets to observe p otentially diagnostic traits of bisected marks, hook scores, and a lack of furrows. Drumheller and Brochu (2014) fed groups of captive alligators partially butchered cow (Bos taurus) hind limbs and pig (Sus scrofa) femora. Scores were found to be the most common types of mark, representing 59.5% of all identified traces. Pits were the second most common marks, representing 31.4% of the recorded marks. Punctures comprised 8.4% of the remaining Table 19.3 Summary of Crocodilian Tooth Mark Morphology Actualistic Studies Baquedano Drumheller Njau and Schneider Westaway et al. (2012) and Brochu Blumenschine (2018) et al. (2011) (2014) (2006) Crocodilian Crocodile (not American Nile crocodile American Saltwater (Consumer) specified; alligator (C. niloticus) alligator (A. crocodile probable Nile (Alligator mississippiensis) (C. porosus) crocodile mississippiensis) [Crocodylus niloticus]) Species Pig and boar Cow (Bos taurus), Goat (Capra White-tailed Pig (Sus scrofa) Consumed (Sus scrofa), sheep pig (Sus scrofa) hircus), cow deer (Odocoileus (Ovis aries), cow (Bos taurus) virginianus), pig (Bos taurus) (Sus scrofa) Total # of marks n = 133 n = 4386 n = 2029 n = 412 n = 43 Pits 57 1205 Not recorded 189 Not noted Scores 65 2282 Not recorded 136 16 Punctures 11 325 Not recorded 55 27 Hook Scores Not noted 141 18 18 Not noted Bisected 33 of 57 pits 125 bisected 205 10 Not noted Marks and 24 of 65 pits; 227 bisected scores were scores, 62 bisected bisected punctures Furrows Not noted 19 Not noted 4 Not noted Percentage of Total Marks Pits 42.8% 31.4% N/A 45.9% N/A Scores 48.8% 59.5% N/A 33.0% 37.2% Punctures 8.2% 8.4% N/A 13.3% 62.8% Hook Scores N/A 6.1% 0.9% 4.4% N/A Bisected 24.8% of all pits 10.3% of all pits, 10.1% 2.4% N/A Marks and 18.0% of all 9.9% of all scores were scores, and bisected 19.1% punctures were bisected Fractures Not noted Observed Not observed Observed Not noted Furrows Not noted 0.1% Not observed 1.0% Not noted Reptile Taphonomy 683 marks, and furrows represented only 0.1% of marks. Of these marks, 10.3% of all pits, 9.9% of all scores, and 19.1% of all punctures exhibited bisections, representing 10.8% of all recorded marks. At least one bisected mark was found on 83.6% of sampled bones. Bisected marks made by American alligators were found in rates similar to C. niloticus: 10.0% of all observed bite marks in C. niloticus and 10.8% in American alligators; 82.5% of individual marks on bones in C. niloticus and 83.6% in American alligators (Drumheller and Brochu 2014). Hook scores comprised 6.1% of all observed scores, were present on 62.5% of the observed bones, and were found at the highest rate in American alligators. Bone fracturing and furrowing created extensively by American alligators are notably rare or absent among C. niloticus and C. porosus. American alligators exhibited a more aggressive style of feed- ing, focusing more on crushing and fracturing prey (Drumheller and Brochu 2014). Size differences of individual crocodilians also may be a factor, as bones/limbs that are swal- lowed whole may require less crushing prior to swallowing. Schneider (2018) utilized five adult and four young American alligators and tested a sample of pig and white-tailed deer (Odocoileus virginianus) bones to compare these tapho- nomic results to those caused by mammalian carnivores. A total of 412 tooth marks were observed on all 37 bones (Table 19.4): 189 pits (45.9%), 55 punctures (13.3%), 136 scores (33.0%), 4 furrows (1.0%), 18 hook scores (4.4%), and 10 bisected marks (2.4%). Edge pol- ish, commonly observed in mammalian carnivore-altered samples, was not recorded, again indicating that this is a not a characteristic of crocodilians (Binford 1981; Njau and Blumenschine 2006; Chapter 9). The edges of all the proximal portions of the pelvis were crushed by the alligators. Table 19.4 Tooth Marks on a Sample (n = 37) of Pig (Sus scrofa) and White-Tailed Deer (Odocoileus virginianus) Bones Caused by American Alligator (Alligator mississippiensis) Feeding Tooth Mark Bone Femur Tibia Humerus Pelvis Ulna Radius portions (n=8) (n=2) (n=3) (n=2) (n=11) (n=11) Pits Proximal 14 3 11 4 0 9 Midshaft 86 0 41 0 7 0 Distal 23 0 0 2 0 2 Punctures Proximal 5 0 8 10 2 3 Midshaft 0 0 0 0 0 0 Distal 10 0 0 1 1 7 Scores Proximal 1 5 0 7 16 0 Midshaft 45 1 7 1 0 3 Distal 6 1 3 2 3 26 Furrows Proximal 0 0 0 1 0 0 Midshaft 0 0 0 1 0 0 Distal 2 0 0 0 0 0 Hook Scores Proximal 0 1 0 0 0 0 Midshaft 9 0 0 3 2 0 Distal 1 0 0 0 0 1 Bisected marks Proximal 0 1 0 0 0 0 Midshaft 9 0 0 0 0 0 Distal 0 0 0 0 0 0 Source: Schneider (2018). 684 Manual of Forensic Taphonomy Baquedano et al. (2012) observed tooth mark frequency and morphology on bone uti- lizing eight captive (zoo) female crocodiles, attempting to verify previous assessments of the degree of bone damage inflicted by crocodiles. The carcass portions included limbs from pig, boar, sheep, and cow. They identified tooth marks using similar criteria to Njau and Blumenschine (2006), dividing the marks into pits, punctures, and scores (including hook scores). A total of 133 tooth marks were observed: 57 pits, 65 scores, and 11 punc- tures. In addition, 33 bisected pits (24.8% of total tooth marks) and 24 bisected scores (18% of total tooth marks) were observed. Baquedano et al. (2012) found that their study supported previous research regarding the degree of damage inflicted by crocodiles while consuming carcasses. More than 80% of elements contained at least one diagnostic tooth mark created by a crocodilian. Crocodilian feeding also can fracture bones. Njau and Blumenschine (2006) described fracture patterns and whole bone breakage, documenting spiral fractures which range from rare (Baquedano et al. 2012) to incomplete (Drumheller and Brochu 2014) from Nile crocodile feeding. Schneider (2018) also observed spiral fracture patterns among bones accessed by young American alligators. Though both the Nile crocodiles sampled by Njau and Blumenschine (2006) and the American alligators sampled by Drumheller and Brochu (2014) measured around 4 m in length, the American alligators caused more extensive damage, so variation by species may occur. In an attempt to verify the patterns of modification described for Nile crocodiles and those of extinct crocodiles, Westaway et al. (2011) conducted a study with three captive saltwater crocodiles using two subadult pig carcasses. Each crocodile was allowed access to a carcass one at a time, and Westaway et al. (2011) observed that the crocodiles exhibited five of the six stages of crocodilian feeding behavior: capture, “kill”, reduction, defleshing, and swallowing. Fracturing of the pig remains was frequent, especially on the axial skel- eton; however, tooth marks on the remains were uncommon and only a few punctures and scores were observed in their sample. Tooth marks that were observed were isolated and mostly found on the skull, pelvis, and long bone epiphyses. Westaway et al. (2011) observed a total of 43 marks: 16 scores (37.2% of total tooth marks) and 27 punctures (62.8% of total tooth marks). Delaney-Rivera et al. (2009) observed tooth marks on a varied sample of taxa and included comparative data from Domínguez-Rodrigo and Piqueras (2003), Selvaggio and Wilder (2001), and Pobiner (2007). Delaney-Rivera et al. (2009) presented 16 omni- vores and carnivores (ranging from small to large in size) with defleshed goat fore- and hind-limbs and presented large carnivores with an additional defleshed cow femur. Their study suggested that only a limited number of inferences about taxa and body size could be made based upon the tooth pit dimensions and location. Different-sized taxa were found to create tooth mark dimensions that overlap in size. Specifically pertaining to crocodilians, Delaney-Rivera et al. (2009) observed bisected tooth pits on remains modified by an alliga- tor, an example of diagnostic tooth mark morphology. Focusing on patterns of shell breakage and behavior specific to chelonivory and not specifically on bite identification, Milàn et al. (2010) observed Dwarf caiman (Paleosuchus palpebrosus) bite modifications on red-eared slider (Trachemys scripta) shells. The caiman was observed manipulating the turtle into an upright position before applying jaw pressure, allowing the shell to be opened and emptied. This maneuver left several bite traces in the shells, including round punctures arranged in rows, elongated scores from teeth scraping along the shell, and large crushed areas from the repetitive bites applied to the same area. Reptile Taphonomy 685 Case Study: Nile Crocodile (Crocodylus niloticus) Scavenging in South Africa In 2012, incomplete skeletal remains of a human juvenile were discovered in the town of Umkomaas, which is located in the KwaZulu-Natal province in South Africa. The pri- mary attraction of the town is the Umkomazi River, which is the largest river on the South Coast of South Africa and is popular for both whale sightings and water sports. Rivers in South Africa are also home for the Nile crocodile, with crocodile attacks occurring to humans most often during the summer months (December to March) (Pooley 2019). The most frequent victims of crocodile attacks tend to be children who use rivers for swim- ming and bathing (Pooley 2019). The specific discovery location of the skeletal elements in Umkomaas was not known, and no photographs of the scene were made available to the forensic anthropologist. Interpretations were therefore limited to the analysis of the avail- able bones. Only 12% (25 bones) of the entire skeleton was recovered, including the pelvis, lower limbs (femora and left tibia), and left foot (Figure 19.12). Using the KidStats program (Stull et al. 2014, 2017), data from the tibia and femur were used to estimate age at death (9–14 years) and sex (female) (Stull et al. 2014, 2017 ). Random and densely packed tooth pits, striations, hook scores, and drag snags were noted on the pelvis, femora, left tibia, and left cuboid (Figures 19.13 and 19.14). In a foren- sic context, crocodilian predation/scavenging on bones can be easily confused with sharp- force trauma and/or dismemberment. Dismemberment is the action of removing body parts, such as head, limbs, hands, and feet, as a means to obscure personal identity, manage dispersal of a body, and sometimes due to a general loathing of the person (Symes et al. 2002). Perpetrators tend to focus on joints or make attempts to cut through entire bones with serrated knives and/or saws. While cutting through soft tissue with a knife, perpetra- tors tend to cut proximal and distal ends of a long bone, leaving distinct V-shaped patterns with potential striations from knife-cut wounds and kerfs from various classes of saws. The presence of these tool marks is often used to exclude terrestrial carnivore activity as a source of these defects. Scores, hook scores, and drag snags created from the anterior dentition of Figure 19.12 Recovered skeletal elements from riverine areas of Umkomaas. Both femoral heads had been removed for DNA analysis by the South African Police Service (SAPS). 686 Manual of Forensic Taphonomy Figure 19.13 Random and dense distribution of hook scores and punctures on the external surface of the left ilium of the os coxa, consistent with Nile crocodile (Crocodylus niloticus). Three hook scores with pivots at a 45° angle (black arrow) are present. Based on the distribution of damage, the crocodile’s grasp had gone across the hips and around the buttocks. Figure 19.14 High density of tooth marks on the distal, lateral left femur, consistent with Nile crocodile (Crocodylus niloticus). Characteristics associated with crocodiles include: (1) intact distal and proximal end of long bones (tibia and femur), (2) a hook score at a 45° angle, and (3) cluster of tooth pits and drag-snags transversely orientated to the long axis of the bone. Reptile Taphonomy 687 crocodilians also present with V-shaped patterns and striations and also tend to cluster along the diaphysis and/or the proximal and distal ends of the bone (Figure 19.14). Anthropologists tend to classify sharp trauma into categories with serrated and non- serrated knives; heavy chopping instruments such as machetes or swords; and various classes of saws, based on the profile, shape, and size of the kerf (e.g., Symes et al. 2002). For an injury to be associated with a sharp force, the wielding tool must have a beveled edge (Symes et al. 2002). A knife is simply defined as a blade with a cutting edge, and the edge must be beveled for it to be considered a tool that creates “knife cuts”. Basically, incised wounds cannot be created unless the blade presents with an edged bevel. As mentioned above, the anterior teeth of crocodilians have carinae, or sharp ridges on the mesial and distal surface (Figure 19.3), which represent an edged bevel that contributes to the observ- able V-shaped defects with striations on the bone. The anterior teeth of extant terrestrial carnivores do not have these sharp, raised ridges of bone, and therefore these predators can only cause blunt force injuries along with punctures and pits on the bone. Three main dif- ferences between human-induced sharp force trauma and crocodilian activity are, for the latter: (1) increased density and randomness of defects on bone in a given area; (2) bisected pits and hook scores; and (3) an absence of dismemberment of the bone at the joints, with intact proximal and distal ends. In this case, the distribution and density of punctures, hook scores, and drag snags are consistent with Nile crocodile predation/scavenging (Figures 19.13–19.17). At least 140 defects were observed on seven skeletal elements, namely the right ilium (n = 14), left ilium (n = 23), left ischium (n = 2), left femur (n = 42), right femur (n = 39), left tibia (n = 18), and left cuboid (n = 2). The left hip (left ilium, Figure 19.13) and left leg (femur) had the greatest number of defects, namely pits, hook scores, and drag snags, on the superior iliac blade and around the anterior superior iliac spine, whereas in the lower limbs the presence of similar Figure 19.15 Close-up view of distal left femur, lateral, with several pseudo-cuts in bone with and without snags are observed (blue arrow), consistent with Nile crocodile (Crocodylus niloti- cus). A drag snag with striations is indicated with the black arrow. 688 Manual of Forensic Taphonomy Figure 19.16 Close-up view of the midshaft of the left tibia, showing pseudo-cuts with- out snags, (pink arrow), as well as hook scores (black arrow), consistent with Nile crocodile (Crocodylus niloticus). A bisected puncture mark (blue box) has an embedded, carinated croco- dilian tooth fragment. defects tended to cluster around the diaphyseal shafts of the long bones. Consistent with the literature on crocodilian predation/scavenging, none of these defects resulted in the complete separation of a bone, or bones, from each other (Baquedano et al. 2012; Njau and Blumenschine 2006; Njau and Gilbert 2016). Only one puncture was noted on the articular surface of a bone (distal left femur), and no other defects were noted around the hip, knee or ankle joints. The left tibia also retained the broken-off tip of a carinated tooth (Figures 19.16 and 19.17), which was clear evidence of crocodile involvement. Other Reptiles Multiple species of monitor lizards, genus Varanus, live throughout Africa, southern Asia, and Oceania, and these have received some study regarding their ability to modify bones. Komodo monitors (“dragons”; Varanus komodoensis) are native to Indonesia and are the largest extant lizard species. D’Amore and Blumenschine (2009, 2012) examined the traces of feeding behavior of captive (zoo) monitor lizards on multiple goat (Capra hircus) carcasses in order to determine the characteristics of marks produced by zipho- dont (“sword tooth”; labio-lingually compressed, distally curved, and serrated) teeth. The most common marks by far were scores, with fewer pits and “edge marks” along the thin margins of bones, and rare punctures and furrows; some marks also included sepa- rate striations from the tooth serrations. Most marks were narrow (<1 mm) but varied in length. Komodo monitors are known to prey upon large mammal species, includ- ing humans (Hart and Sussman 2008:124–127). Smaller lizard species likely lack signifi- cant bone modification behavior or ability, but further taphonomic experimentation is required to test this assumption. Reptile Taphonomy 689 Figure 19.17 Jagged scores on the anterior midshaft of the left tibia, which are consistent with Nile crocodile (Crocodylus niloticus). A bisected puncture mark (white box) has an embedded, carinated crocodilian tooth fragment. Other reptile species have not been examined in detail for their bone modification behavior; in particular, two species of turtle (Order Testudines) that are common in the USA, snapping turtle (Chelydra serpentina) and alligator snapping turtle (Macrochelys temminckii) and their relatives in the family Chelydridae in Central and South America. Snapping turtles are found throughout the eastern two-thirds of the USA and into south- ern Canada and northeast Mexico and have a broad, omnivorous diet that includes inverte- brates, vertebrates, and scavenging; adults ambush hunt small prey (Spotila and Bell 2008). Alligator snapping turtles are confined to southern climates centering on the Mississippi basin, from Texas to Florida (Ernst 2008) and have a similarly broad diet that also includes at least some scavenging (East and Ligon 2013). Both species are therefore possible scav- engers of human remains in wetlands and adjacent terrestrial environments, and direct observational studies of wild turtles with bait carcasses are necessary to assess their poten- tial impacts upon soft tissue, markings upon bone, and dispersal. Acknowledgements The authors thank the Forensic Anthropology Program, Boston University School of Medicine, for their funding support, and the staff at Edisto Island Serpentarium, Ken Alfieri, Trish McCoy, Ted Clamp, and Hayward Clamp for their access to their alligator population and support throughout the feeding experiments conducted there. 690 Manual of Forensic Taphonomy References Alderton, D. (1991) Crocodiles and Alligators of the World. Facts on File, New York. 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