Zooarchaeology Study Guide

📖 Core Concepts Zooarchaeology – the interdisciplinary study of animal remains (bones, shells, hair, etc.) from archaeological sites to reconstruct past human‑animal interactions and environments. Taphonomy – the study of processes that modify biological material after death (burial, weathering, scavenging, cut marks, burning, etc.). Identification & Taxonomy – matching bone fragments to anatomical elements and to species using Linnaean classification; when fragments are too small, broader taxonomic categories are applied. Quantification Metrics NISP (Number of Identified Specimens): simple count of each identified bone fragment. MNI (Minimum Number of Individuals): smallest possible number of animals that could produce the observed element counts. MNE (Minimum Number of Elements): smallest number of each skeletal element needed to account for the fragments. Genetic Analyses – extraction of ancient DNA (aDNA) to track population movements, domestication, and adaptation; requires strict contamination control. ZooMS – “Zooarchaeology by Mass Spectrometry”; identifies species from collagen peptide fingerprints, useful for highly fragmented bone. --- 📌 Must Remember Bones & Shells are the most common preserved faunal parts; hair, scales, DNA often degrade. Cut marks → human butchery; percussion fractures → marrow extraction; spiral fractures → intentional breakage. NISP bias: over‑represents species with many survivable elements; fragmentation inflates counts. MNI rule: take the highest quotient of element count ÷ elements per individual (usually 1 for most bones). aDNA is short, highly susceptible to contamination → clean‑lab protocols are mandatory. ZooMS works only when collagen survives (generally < 5 Ma depending on preservation). --- 🔄 Key Processes Taphonomic Assessment Record surface modifications (cut marks, gnawing, burning). Identify non‑human agents (raptors, rodents, fungi, root etching). Infer burial conditions and post‑depositional alterations. Identification Workflow Sort fragments by size & morphology. Match to reference osteological collections → assign element & species (or higher taxon). Note age/sex indicators (epiphyseal fusion, tooth wear, pelvis morphology). Quantification Routine Count NISP for each taxon. Compute MNI: \[ \text{MNI} = \max\left(\frac{N{\text{element}}}{n{\text{per individual}}}\right) \] Compute MNE by summing the most complete sets of each element. Molecular Analysis Extract DNA → PCR amplify short loci → compare to reference genomes. For ZooMS, digest collagen → MALDI‑TOF MS → match peptide mass fingerprint to species library. --- 🔍 Key Comparisons NISP vs. MNI NISP = raw counts (easy, but biased). MNI = conservative estimate of individuals (reduces fragmentation bias). Cut Marks vs. Gnaw Marks Cut marks: V‑shaped, linear, often on long bones near joints. Gnaw marks: irregular, U‑shaped, associated with teeth pits. aDNA vs. ZooMS aDNA: provides genetic lineage, population data; needs well‑preserved DNA. ZooMS: species ID from protein; works when DNA is too degraded but collagen persists. Wild vs. Domesticated Species Wild: broader size variation, may show seasonal hunting patterns. Domesticated: more uniform size, evidence of herd management, possible age/sex bias. --- ⚠️ Common Misunderstandings “Higher NISP = higher dietary importance.” – Fragmentation and bone density bias NISP; use MNI/MNE for more reliable diet reconstructions. “All cut marks mean cooking.” – Cut marks indicate butchery; cooking evidence comes from burning patterns, pot‑shards, etc. “aDNA works on any bone.” – DNA degrades quickly; hot, humid, or acidic soils often destroy it. “MNI always overestimates individuals.” – MNI can underestimate if multiple skeletal elements are missing or misidentified. --- 🧠 Mental Models / Intuition “Faunal assemblage as a jigsaw puzzle.” Each fragment is a piece; the more pieces you correctly place (identification), the clearer the picture of past subsistence and environment. “Taphonomy as a forensic timeline.” Think of each surface modification as a clue about who (human vs. animal) and when (pre‑burial vs. post‑burial) acted on the bone. “MNI = tallest column in a bar chart.” When you plot element counts, the tallest column (after adjusting for elements per animal) gives the minimum number of individuals. --- 🚩 Exceptions & Edge Cases Highly fragmented assemblages – NISP may be dramatically inflated; rely on MNI/MNE or ZooMS. Collagen loss – ZooMS fails in very old or heavily burned specimens; aDNA may also be absent. Sex determination – Only possible on species with sexually dimorphic pelvis or horn cores; many mammals lack clear markers. Transport bias – Remote sites often contain only high‑utility elements (e.g., limbs), skewing species representation. --- 📍 When to Use Which | Question | Preferred Method | |----------|------------------| | Quick taxonomic overview of an assemblage? | NISP (fast count) | | Estimate minimum individuals for demographic studies? | MNI (conservative individual count) | | Need element‑specific abundance (e.g., limb vs. skull)? | MNE (element count) | | Species ID from tiny, unidentifiable fragments? | ZooMS (collagen fingerprint) | | Reconstruct population genetics, migration, or domestication? | aDNA (genetic sequencing) | | Determine if bone modifications are human‑made? | Taphonomic analysis (cut vs. gnaw marks) | --- 👀 Patterns to Recognize Cluster of cut marks on long‑bone diaphyses → systematic butchery for meat removal. High frequency of spiral fractures on limb bones → marrow extraction behavior. Over‑representation of robust elements (e.g., femur, tibia) → selective transport of high‑meat parts. Presence of both domesticated and wild species in the same layer → mixed economy (herding + hunting). Consistent age‑profiles (e.g., many juvenile remains) → herd management or selective hunting of young animals. --- 🗂️ Exam Traps Distractor: “NISP is unbiased because it counts every specimen.” Why wrong: Differential preservation and fragmentation cause NISP to over‑represent some taxa. Distractor: “Cut marks always indicate cooking.” Why wrong: Cut marks show butchery; cooking is inferred from burning, pot‑shards, or heat‑altered collagen. Distractor: “MNI is always higher than NISP.” Why wrong: In highly fragmented assemblages, NISP can exceed MNI; they measure different things. Distractor: “If collagen is present, ZooMS will work on any sample.” Why wrong: Collagen may be degraded enough for detection yet insufficient for clear peptide patterns; also contamination can obscure results. Distractor: “Ancient DNA can be amplified from any bone fragment.” Why wrong: DNA preservation depends on temperature, pH, and time; many samples yield no recoverable DNA. ---