Reports from the Environmental Archaeology Unit, York 98/29, 11 pp. Assessment of invertebrate remains from ‘tree pits’ in Selby (site code SDC97) by John Carrott, Deborah Jaques, Harry Kenward and Darren Worthy Summary Six samples from medieval and post-medieval organic-rich deposits revealed during excavation of pits for tree-planting in central Selby have been investigated for invertebrate macrofossils. All contained at least some insect remains and a range of other invertebrates, and each deposit would yield an interpretatively useful assemblage from a subsample of 3-5 kg. Preservation was generally good. The deposits seem to have formed in the open, with dumping of organic waste, some perhaps domestic and some probably stable manure. Conditions seem to have been muddy and puddles may have existed from time to time. Further investigation is recommended. Keywords: SELBY; MEDIEVAL; POST-MEDIEVAL; INVERTEBRATES; INSECTS; MUD; PUDDLES; STABLE MANURE; HOUSE FAUNA Authors’ address: Prepared for: Environmental Archaeology Unit Alison Clarke University of York 18 Ash Grove Heslington Northallerton DL6 1RQ York YO10 5DD 19 August 1998 Reports from the EAU, York 98/29 Assessment: Selby Tree Pits Assessment of invertebrate remains from ‘tree pits’ in Selby (site code SDC97) Introduction The material is considered in context order. Information provided by the excavator is given A selection of samples from deposits of in square brackets. Preservation of medieval to post-medieval date revealed invertebrate remains was generally good. during archaeological excavation of a series of pits for tree-planting in central Selby, North Context 3326 [Occupation layer - ?leather Yorkshire, was submitted to the EAU for working; black and brown organic silt assessment of invertebrate remains. containing large quantities of leather; pottery in 14th-17th century range] Methods Laboratory description: Moist, mid grey- brown brittle (working soft) slightly sandy clay Samples from six contexts were examined for silt, browner and greyer in patches, with a insect remains and other macro-invertebrates. patch of coarse sand, stones (2-60 mm), tile, Following a description (using a pro-forma), coal (to 25 mm), twigs, a large, well-preserved subsamples of the sediment were sieved to fragment of leather, and marine mollusc shell. 300 microns and invertebrate remains Subsample of 1.6 kg processed. extracted using paraffin flotation (Kenward et al. 1980, as modified by Kenward et al. Invertebrates: A substantial assemblage of 1986). Although this was an assessment it was invertebrate remains was recovered; the considered worthwhile to record the material was scan recorded. In addition to assemblages in more detail than the usual 109 individuals of 60 taxa of adult beetles and ‘assessment recording’ in order to provide bugs there were abundant mites and smaller data for synthesis; two groups were ‘scan numbers of a range of other invertebrates, recorded’ and the remainder ‘rapid-scan including three kinds of water-flea (Cladocera) recorded’ (sensu Kenward 1992). Data were resting eggs and an unidentified flea body entered to a PARADOX-based system which segment. produces species lists and summary statistics for the assemblages. The beetles were notable for the abundance of oxyteline staphylinids: the most numerous taxon was Carpelimus pusillus group (9 Results individuals), with Anotylus nitidulus (8), an unidentified Carpelimus (4), C. ?bilineatus, Species lists are given in rank order for each Platystethus arenarius, P. degener and assemblage in Table 1, and main statistics for Anotylus tetracarinatus (all 3), P. alutaceus the assemblages of adult beetles and bugs in and P. nitens (2 each), C. ?rivularis and Table 2. The ecological and other codes Oxytelus sculptus (both 1). Most of these are employed are explained in Table 3. species normally found in damp waterside litter and mud at the present day (P. arenarius and O. sculptus being associated with dung and artificial accumulations of foul matter, however). It might be argued that this Sample-by-sample account characteristic group formed as a result of the accumulation of ‘background fauna’ since Reports from the EAU, York 98/29 Assessment: Selby Tree Pits these are all very migratory species (this was Invertebrates: Rather few invertebrates were suggested by Kenward 1978, 7, for example). present, but there was a subjective affinity However, it seems likely that they bred in the with the fauna recorded for the sample from ‘muddy’ organic-rich accumulating deposit at Context 3326; oxyteline staphylinids the present site, as has been suspected for (Anotylus, Carpelimus and Platystethus some other sites, such as 5-7 Coppergate, species) were prominent. This may have been York (Hall et al. 1983). Water beetles were largely background fauna, but it is possible fairly numerous but it is not clear whether they that communities of beetles including the had colonised small pools or were accidental oxytelines exploited muddy conditions on arrivals (i.e. background fauna). The water- surfaces. A much large subsample (5 kg or flea resting eggs may indicate short-lived more) would produce an interpretatively puddles, but could conceivably have resulted useful assemblage. from the disposal of waste water or even have entered in animal dung (having been taken in accidentally while drinking). Context 3639 [Layer; mottled mid to dark brown silt, woody with occasional stones The remaining fauna included a range of (mainly small), shell and tile; pottery in 15th- species which seem most likely to have 16th century range] originated in horse dung or scattered stable manure - the grain pests Oryzaephilus Laboratory description: Just moist, light-mid surinamensis and Sitophilus granarius, grey-brown, brittle to crumbly (working soft together with ‘house fauna’ components and when wet), slightly sandy slightly clay silt with small numbers of characteristic decomposers an orange tinge in places. Brick/tile, ?vivianite, associated with open-textured foul matter (the rotten organic matter and twigs were present. recognition of stable manure is discussed by Subsample of 0.95 kg processed. Rapid-scan Kenward and Hall 1997). recorded. This assemblage gives a strong impression of Invertebrates: Modest numbers of remains a damp, muddy area with much organic were present. Grain pests were among the matter, probably stable manure, and no more commonest beetles, but the fauna was very than rare weeds. mixed, perhaps including a substantial background component. Two taxa associated with wood were present: the flatbug Aneurus Context 3452 [Brushwood or wattle fence; ... sp. (found under loose bark) and the bark twigs and small branches, laid horizontally beetle ?Leperisinus varius (which bores in ash twisted round and laid against small ... upright trunks and branches). A larger subsample stakes; pottery in 12th-16th century range] (perhaps 5 kg) would provide an assemblage which would give a clearer view of conditions Laboratory description: Just moist, mid grey- at the point of deposition. brown, brittle to crumbly (working soft), slightly sandy silt with dark grey and dark Context 3657 [Layer; compacted dark grey- brown patches internally; clear content of black organic silt with some wood and high well-decayed organic matter. Some very percentage [of] cinder; pottery in 14th-15th rotten wood and some fly puparia. Subsample century range] of 0.95 kg processed; rapid-scan recorded. 3 Reports from the EAU, York 98/29 Assessment: Selby Tree Pits Laboratory description: Dry, layered and Invertebrates: The assemblage was scan- crumbly (working soft when wet), humic recorded. There were 76 adult individuals of slightly sandy silt, varicoloured from light 43 beetle and bug taxa of the groups used in grey-brown to mid grey-brown to mid to dark preparing assemblage statistics, together with brown to black. Stones 20-60 mm and small numerous mites and fly puparia, and a range of fragments of mica present. Subsample of 0.65 other remains including a human flea (Pulex kg processed. Rapid-scan recorded. irritans). Grain pests were numerous (ten Oryzaephilus surinamensis and five Sitophilus Invertebrates: A small group of invertebrates granarius), and there was a clear house fauna was recorded. The overall impression was that component including Lathridius minutus most of the fauna originated within a building, group (10), Mycetaea hirta (3), Ptinus ?fur for a range of ‘house fauna’ taxa (sensu and Cryptophagus sp. (2 each) and single Kenward and Hall 1995, 662-667) was individuals of several other taxa. A hint of the present. Notable among these were Lathridius presence of hay was offered by the stiltbug minutus group (6 individuals), Mycetaea hirta Berytinus sp. and the ‘clover weevil’ Apion and Aglenus brunneus (both 2), ?Xylodromus sp., and perhaps by the click beetle Agriotes concinnus, Tipnus unicolor, Cryptophagus sp. (all single individuals). These three ?scutellatus, two Atomaria species, Tenebrio components rather suggest the presence of ?obscurus and the human flea Pulex irritans stable manure. There were a few decomposers (all 1). The presence of Oryzaephilus associated with foul matter, and a trace of surinamensis (2) and Anthicus floralis or water flea resting eggs. A larger subsample (of formicarius (1) offers a hint (no more) that 3-5 kg) would undoubtedly clarify the this deposit included stable manure, but it may interpretation. have been house floor material. The sheep louse Damalinia ovis was recognised; it probably originated