Invertebrates: Insects and Molluscs

Question 1

Archaeomalacology

Answer 1

Study of the remains of molluscs in the archaeological record

Question 2

Identification of Molluscs

Answer 2

• Soft unsegmented body and CaCo3 exoskeleton
• Not all have shells (slugs)

Question 3

8 different mollusc orders in the mollusc class

Answer 3

Domain - Kingdom - Phylum - Class - Order - Family - Genus - Species

• Aim to identify down to the species level
• Terrestrial molluscs: often only identify to family or at most genus
• Freshwater shells: identify to genus and species
• Phylum Mollusca: grouped by morphology and behaviour into classes and sub-classes
• Over 160,000 known species

Question 4

Mollucs of most interest

Answer 4

• Gastropoda and Bivalvia
• More likely to come across on archaeological sites
• Most other molluscs don’t have exoskeletons or internal components that survive

Question 5

Recovery and identification of molluscs

Answer 5

• Most shells will be hand collected during species excavation
• Smaller shells may be recovered through floatation
• Recorded as small finds
• Wet sieving

Question 6

When might shell preservation be limited

Answer 6

In acidic environments

Question 7

Why might it be hard to identify terrestrial gastropods down to species level

Answer 7

Species specific traits often in soft tissues

Question 8

What should be considered when using shell remains to reconstruct past cultural/social activities and environments

Answer 8

• First: consider biostatinomy, all processes that affect the assemblage after organism death
• What agent was responsible for shell accumulation? cultural vs natural
• Actions of sea birds are problematic: create large species-selective, highly fragmented shell assemblages
• Storms, tsunamis, floods

Question 10

Human use of shells

Answer 10

• Analogues are drawn from records of recent or historically documented group
• Among non-industrial groups, shell adornments often convey social information, including group affiliation
• Ethnographic record suggests 4 main uses: food, fish bait, raw material, currency

Question 11

Shell as raw material

Answer 11

• Commonly used for fishhooks and lures in traditional fisheries
• Fish familiar with appearence and smell
• Bivalves exploited for sharp cutting edges
• Large species used as vessels, spoons, trumpets
• Shell beads and personal adornments
• Nacreous interior surface or decorative exterior
• Unusual shape, texture, or rarity

Question 12

Shellfish as food, historically

Answer 12

• In historic times, shellfish were often exploited during times of scarcity and prized in communities for creating variety in diet
• Shell fishing undertaken by women and children, less prestigious than hunting
• Predicatble resource and source of protein

Question 13

Insect remains: class insecta species classification

Answer 13

Domain - Kingdom - Phylum - Class - Order - Family - Genus - Species

• Most abundant animal class, approx 75% of all extant species
• Over 1 million species
• Grouped by morophology and behaviour into sub classes
• Focu on beetles and flies, most commonly encountered in archaeology

Question 14

Palaeoentomology

Answer 14

look at insects remains to reconstruct past environments

Question 15

Archaeoentomology

Answer 15

Look at insect remains to reconstruct human behaviour

Question 16

Preservation of insect remain

Answer 16

• Exoskeleton made of chitin
• Polysaccharide
• Chemically inert
• Extremely durable

Best preserved in:
- Permanently wet conditions
- Permenantly dry conditions
- Acidic to neutral pH
- E.g. peat bogs, lakes, rivers, clays, permafost
- Abdomen mot often found, potentially wing cases, head is wanted for identification but not always the best preserved component

Question 17

Recovery of insect remains

Answer 17

• Most will be recovered with floatation tanks
• Less dense materials float to the water surface
• Float residues are collected in a small meshed sieve
• Paraffin floatation is the most widely used technique
• Remains should be preserved in ethanol

Question 18

Why are insects of interest to archaeologists

Answer 18

• Specialists are of particular interest, they are species that inhabit specific ecological niches
• Synathropic species that reflect human habitats/activities
• Grain weevils only inhabit human food stores
• Implicit assumption: ecological niche preference/tolerance remains constant over time
• Assumung contemporary species behaviours are the same as the past

Question 19

Synathropic species

Answer 19

• 5000+ species
• Human ectoparasites: 3 species of Pthiraptera are synanthropic
• Indicators of sanitary conditions

Question 20

Lice as synanthropic species

Answer 20

• Indicate the timing of the first use of clothing
• Genetic age of body lice vs head lice
• Body lice evolved from head lice
• They needed shelter, needed fitted clothing to survive
• Species split 100-700,000 years ago
• Lice have a relatively soft bodt and are only preserved under exceptional conditions
• Knit combs today look the same as Egyptian coptic bone combs

Question 21

Pathogen vectors:
- Trench fever
- Typhus

Answer 21

• Trench fever:
• Recurrent high fever, severe headaches, rash
• Typhus:
• High fever, severe headaches, rash, vomiting, diarrhoea, gangrene, organ failure