Vertebrate Fossil Preparation

Consolidation of fragile fossil bone from Ukhaa Tolgod, Mongolia (late Cretaceous) with Conservare OH 100

by Amy Davidson

Bisulca, C., Kronthal Elkin, L., and A. Davidson. 2009
Journal of the American Institute for Conservation 48: 37–50.

The PITT pen, a possible option for labeling fossil vertebrates

by Amy Davidson

Davidson, A. and M. Fox. 2011.
Society for the Preservation of Natural History Collections (SPNHC) newsletter 25(1): 23-28.

Assembling an Archival Marking Kit for Paleontological Specimens

by Amy Davidson

A.R. Davidson, S. Alderson, M. Fox 2006
Poster presentation, Society of Vertebrate Paleontology annual meeting
Ottawa, ON, Canada

abstract published in:
Journal of Vertebrate Paleontology, Vol.26, Supplement to Number 3,
11 September, 2006, p.56A

Will the number you put on your specimen, its tag, box or other housing, be legible in one hundred years? Is it... more Will the number you put on your specimen, its tag, box or other housing, be legible in one hundred years? Is it rub-proof, water -proof, fade-proof? Will a future worker be able to remove it if necessary?
This poster will present a plan for assembling an archival marking kit, adapted for fossils from a similar kit for anthropological objects. Having a well-designed kit saves time, and can help to improve and standardize marking practices. The proposed kit includes a variety of high quality materials, including India ink, acrylic paint, Acryloid/Paraloid B72 in a convenient nail-polish bottle and also in a tube, Japanese and archival papers, Bristol board, and various dispensers, brushes, pens etc. Possible additions to the kit (such as disposable pens) will be discussed.
Even the best materials can fail if not used well! This poster illustrates marking failures and solutions for problematic fossil surfaces (dark, rough, friable, very small or fragile, etc.), and problematic materials such as coated surfaces and plastics. Also included are a discussion of permanence and removability, looking both at the materials included in the kit and others that could be used or have been used in the past.

An Introduction to Solution and Reaction Adhesives for Fossil Preparation

by Amy Davidson

Davidson, A. and S. Alderson. 2009.
In: Methods In Fossil Preparation: Proceedings of the First Annual Fossil Preparation and Collections Symposium, pp 53-62. Brown, M.A., Kane, J.F. and W.G. Parker eds.

The Use of Cyclododecane to Protect Delicate Fossils During Transportation

by Amy Davidson

Brown, M. and A. Davidson 2010
Journal of Vertebrate Paleontology 30(1):300-303

Preparation of a Fossil Dinosaur

by Amy Davidson

Davidson, Amy R. 2003.
American Institute for Conservation, Objects Specialty Group Postprints 10: 49-61.

Acid treatment effects on the stable isotopic signatures of fossils

by Jo Hellawell

Jo Hellawell and Chris J. Nicholas
Palaeontology

Published online 17 October 2011
DOI: 10.1111/j.1475-4983.2011.01108.x

Prior to geochemical analyses, fossil bones and teeth are often extracted from any surrounding lithified sediments... more Prior to geochemical analyses, fossil bones and teeth are often extracted from any surrounding lithified sediments using chemical techniques such as immersion in acid. As stable isotope analysis becomes more commonplace in palaeoecological investigations, it is important to consider what effects these chemical preparation techniques may have on any subsequent isotopic data and to constrain these effects as quantitatively as possible. This study aims to elucidate these effects, as it is vital that variability in a data set should not be introduced as a result of protocols used during sample preparation; in addition, it defines the most effective and viable method of carbonate removal for processing bulk fossil samples without causing alteration of their stable isotopic signatures. Various strengths of two weak acids commonly used during palaeontological preparation were tested to evaluate their effects on the δ15N and δ13Corg isotopic signatures of the vertebrae of a large Eocene fossil fish. Changes in the isotopic values occurred over time regardless of which acid was used, each causing a variable response in both δ15N and δ13Corg isotopic values. Without careful monitoring of the acidification process in a controlled environment, any resulting data could therefore confound interpretation. Based on these experiments, it is recommended that 2 m acetic acid be used for the pretreatment of fossils prior to the acquisition of N and C isotope data where carbonate removal is necessary.

Literally a ‘mammoth task’: The conservation, preparation and curation of the West Runton Mammoth skeleton

by Nigel Larkin

By Nigel Larkin. In Quaternary International. Available online 15 July 2010.

The skeleton of the West Runton Mammoth is one of only a very few Mammuthus trogontherii skeletons known globally. It... more The skeleton of the West Runton Mammoth is one of only a very few Mammuthus trogontherii skeletons known globally. It is the most complete skeleton of this species known, was excavated in primary context, is well preserved and represents an important stage in mammoth evolution. Therefore this skeleton and the associated specimens from the 1995 excavation at West Runton required relevant levels of conservation, preparation and curation appropriate to material of this importance. As the material is sub-fossil in nature (i.e. not mineralised), biomolecule retrieval techniques may be used on the specimens in the future, and therefore it was necessary to preserve the biochemical and geochemical integrity of the material and invasive conservation procedures such as consolidation were therefore kept to a minimum. However, due to weathering and trampling at the time of burial and subsequent compaction of the sediment the bones were mechanically weak, fragile and vulnerable once excavated. Given the huge size and substantial weight of the larger bones, innovative storage solutions had to be devised to create appropriate permanent supportive storage media. Whilst considering suitable conservation strategies, investigations into certain materials lead to experimentation with techniques.

This project demonstrates the importance of having a well-funded post-excavation conservation programme employing a preparator–conservator not only to appropriately stabilise and conserve the physical material for detailed study but also to conserve information that might otherwise be lost e.g. orientation of bones when found, or the preservation of sedimentary structures. In addition, familiarity with the material resulting from several years of preparing the bones under a microscope has revealed important aspects of the material– relating often to taphonomy and pathology – that might otherwise have been missed.

Article Outline
1. Introduction
1.1. Conservation of the first finds
1.2. Conservation in the field during the 1995 excavation
2. Condition of the material
3. Preparation methods
4. Remedial and preventive conservation methods
5. Storage methods
6. Storage environment
7. Documentation
8. The future of the material
9. Discussion
Acknowledgements
References

The virtual and physical preparation of the Collard plesiosaur from Bridgwater Bay, Somerset, UK.

by Nigel Larkin

by Nigel Larkin, Sonia O'Connor and Dennis Parsons. 2010. The Geological Curator 9 (3): 107 - 116.

The 'Collard Plesiosaur', found in 2003 in Bridgwater Bay on the Somerset coast is the only complete and fully... more The 'Collard Plesiosaur', found in 2003 in Bridgwater Bay on the Somerset coast is the only complete and fully articulated plesiosaur skeleton to have been found in Britain for over 100 years. The 1.5 metre long specimen was preserved in the finegrained and thinly laminated Lower Liassic Kilve Shales. This lithology is susceptible to fluctuations in humidity, severely compromising the integrity of specimens once dry. The priorities for the project were to arrest shale delamination caused by environmental fluctuations and to prepare the specimen for research. The specimen appeared to be mostly well fossilised in a homogeneous, un-cemented matrix, offering excellent potential for non-destructive recovery of fossil information using conventional X-radiography and Computed Tomography before the preparation commenced. Despite the skeleton being variably mineralised, the analyses yielded very detailed images. This 'virtual preparation' helped to inform the subsequent physical preparation, with the conventional radiographs proving most useful. In addition, the project demonstrated that such analyses are not just useful for guiding preparation
but also for recording material that might be removed during preparation and highlighting details not visible to the naked eye or that remain buried. During preparation, experimental attempts to consolidate matrix samples were unsuccessful - the shale layers distorted and delaminated. However, the adhesive Paraloid B72 was successfully applied to the sides of the specimen blocks in liberal quantities, providing a useful partial barrier to future changes in atmospheric relative humidity. Scalpels were found to be the most appropriate tools for preparing the specimen, removing one paper-thin layer of shale at a time.

MARINE FISHES FROM THE LITHOGRAPHIC LIMESTONES OF THE EL MINISTERIO QUARRY, LOS CATUTOS MEMBER (UPPER JURASSIC, VACA MUERTA FORMATION), ARGENTINA. A PRELIMINARY TAPHONOMIC APPROACH

by Soledad Gouiric-Cavalli

GOUIRIC-CAVALLI, Soledad; CABRERA, Daniel Alfredo and CIONE, Alberto Luis

Los Catutos Member is a stratigraphic set composed by lithographic limestones interbedded with marls (rhythmites). At... more Los Catutos Member is a stratigraphic set composed by lithographic limestones interbedded with marls (rhythmites). At El Ministerio quarry (type locality of the Los Catutos Member) the deposits reach a maximum thickness of 70 m. They were deposited in an open and shallow sea (ca. 30-50 m of depth) during the middle to upper Tithonian, and were assigned to a transitional-outer ramp.
El Ministerio quarry is located near to Zapala, Neuquén Province. It presents a high fossil concentration in which, among the vertebrates, fishes are predominant but marine reptiles are also found. Among macroinvertebrates, ammonoids are the most common taxa (five ammonites zones were recognized), among microinvertebrates, the planktonic ones (radiolarians and foraminifers) are predominant. Benthonic organisms (e.g. equinoderms, ostracods, gastropods) are scarce. Diffuse bioturbation is present in some banks. The water conditions were inferred as warm-temperate, and the micritic/clastic input rate was high. The distance to the shoreline was 100 km without evidence of reef development.
In the present contribution, we analyzed 61 specimens from the lithographic limestones of El Ministerio quarry. We found that pachycormiforms are predominant (43% of specimens), followed by semionotiforms (13%), and aspidorhynchids (13%). Only 10% are represented by halecomorphs (caturid-like), teleosts-like and “pholidophorids”-like and the 21% of remaining specimens correspond to indeterminate actinopterygians. About 67% of specimens correspond to body fragments, 25% to complete skeletons, and 8% to isolated bones. Fishes are found articulated (39%), partially disarticulated (36%), disarticulated but associated (23%) and rarely scattered but associated (3%). Among partially disarticulated specimens, 27% have disarticulated skull bones, 9% have disarticulated bones and scales in the abdominal region and 14% a combination of both. About 62% of the fishes have scales preserved; most of them (58%) show scales in situ. Most of the fishes lie with their symmetry plane parallel to the bedding plane (64%). In those fishes with preserved vertebral column, deformation of the axial skeleton is variable (straight, 53%; arched, 27%; S-shaped, 7%; broken, 7%). Almost 47% of specimens present articulated fins (mainly caudal and pectorals). No signs of scavenging were observed.
Interpretation of the data set reveals that the specimens with articulated or partially articulated skeletons, with preserved fins and scales (mostly in situ), suggest a short to very short time of residence on the substrate, and a lack of bottom currents and an early decomposition. Detached bones or scales near to the skull or even the abdominal region thoroughly disarticulated are considered to be caused by bacterial decay. This involves that carcasses remained longer on seafloor uncovered by sediments than the articulated ones. Besides, only few specimens have experienced flotation and subsequent disarticulation (e.g. detached skulls with the symmetry plane perpendicular to the bedding plane, dispersed bones). Most of fishes have no signs of post-mortem deformation of vertebral column; few specimens present arched skeletons due to a natural post-mortem condition.
In sum, taphonomic features of the fossil assemblage indicate that fishes were deposited in a quiet disaerobic bottom in absence of scavengers, in which rapid burial and early interruption of decay processes allowed the good preservation of fossils. We infer that they possibly were coeval and that the association is autochthonous.

Preparation techniques applied to a stegosaurian Dinosaur from Portugal

by Octávio Mateus

R Araújo, O Mateus, A Walen, N Christiansen. 2009. Preparation techniques applied to a stegosaurian Dinosaur from Portugal. Journal of Paleontological Techniques 5: 1-24.

DIFFICULT EXCAVATION AND PREPARATION OF A LARGE DASPLETOSAURUS SPECIMEN

by Anthony Maltese

PROCEEDINGS OF THE FIRST ANNUAL FOSSIL PREPARATION AND COLLECTIONS SYPOSIUM

A difficult combination of soft matrix, soft fractured bone, low overburden, plant root damage, weathering and... more
A difficult combination of soft matrix, soft fractured bone, low overburden, plant root damage, weathering and
a high degree of specimen articulation posed  special problems in the recovery of a  Daspletosaurus torusus
Russell skeleton, RMDRC 06-005. Traditional jacketing methods yielded unsatisfactory results, therefore the
Pallet method was used to remove large numbers of  inseparable elements. Mechanical preparation proved
impossible without consolidation of both the fossil material and the surrounding matrix with low strength
cyanoacrylate adhesives. Preparation was then accomplished mainly by air abrasion

Preparation records: Rationale, reality and relational databases

by Gregory Brown

Brown, Gregory W., SVP 2001. Journal of Vertebrate Paleontology, Abstracts of Papers. Vol. 21, Supplement to Number 3, p. 36A.

Recording and maintaining preparation and conservation records of specimens has long been recognized as an essential... more Recording and maintaining preparation and conservation records of specimens has long been recognized as an essential component of responsible collection management and care. The overhead imposed by additional paperwork and the limitations of existing collection databases, however, have resulted in a general reluctance by many preparators and curators to adopt any meaningful record system whatsoever. At the University of Nebraska State Museum, a preparation record system has evolved that minimizes these effects by limiting record fields to those deemed most critical and by designing dedicated preparation/consevation and mold/cast databases. Emphasis is placed upon recording factors that could effect the chemical and physical stability or research potential of specimens. These factors include materials that are either applied to the specimen (mold materials, separators, setup clays, etc.) as well as the preparation techniques employed. Record sheets are designed to minimize the time and effort needed to record data. Database design accommodates the vagaries of specimens in various stages of curation, and entry and search forms allow easy access to all records. Preparators, collection managers and curators, althought usually not trained as conservators, must take a conservation-minded approach to preparation and collections management in order to assure long-term integrity of the specimens in their care. Accurate preparation records fulfill a primary requirement of this approach.

Silicone RTV rubber molds and deep recesses: Conquering the tear

by Gregory Brown

SVP 1986

Bone bandages: A conservationally-sound repair technique for broken bones having limited contact surface area

by Gregory Brown

Brown, Gregory W., 2010. Journal of Vertebrate Paleontology Vol. 30, Supplement to No. 3, Abstracts of Papers

Traditional methods of repairing broken fossil bones that have significant sections missing from the surfaces to be... more Traditional methods of repairing broken fossil bones that have significant sections missing from the surfaces to be joined include using gap fillers such as plaster or epoxy and internal reinforcement such as wooden dowels or metal rods. Broken bones that have a limited contact surface area relative to the stress to be experienced by the join have often been repaired using external reinforcements such as metal wires or rods adhered to the bones with various polymers. While some of these techniques may occasionally be necessary for very large, heavy bones destined for self-supporting display, they are seldom needed or appropriate for small to moderate sized research specimens. Such methods suffer from several disadvantages: Filling voids can obscure potentially significant internal features or the true nature of the element; removal of traditional gap fillers or repairs to partially failed joins are often difficult or impossible without damaging the specimen; incompatible materials may actually exacerbate stress and damage to the specimen. Lightweight woven or mat (veil cloth) fiberglass or polyester fiber strips saturated with a 1:2 solution (w/w) of Paraloid B-72 in acetone and applied externally across a join or unfilled gap will greatly increase the effective surface area of the join while significantly improving shear and tensile strength and, when applied in opposition, bending strength as well. These “bone bandages” eliminate the need for gap fillers or reinforcement rods, minimally obscure both surface and internal features, are easily reversible and are stable over time. This technique is also appropriate as a preventative reinforcement for very thin, unbroken bone which might not otherwise survive normal preparation or handling.

An infinitely-adjustable work stage for precision preparation of microfossils under high magnification

by Gregory Brown

Brown, Gregory W., 2011. Proceedings of the 4th Fossil Preparation and Collections Symposium, Kemmerer, WY.

Preparing microfossils under high magnification (40X+) presents the preparator with several problems. Optical depth of... more Preparing microfossils under high magnification (40X+) presents the preparator with several problems. Optical depth of field is reduced significantly; without a rigid work stage, even gentle tool pressure may move the specimen out of focus. Preparator tool control is critical for preparing minute specimens and is dependant upon hand position; without the ability to easily re-orient the specimen, the awkward hand positions required to accommodate different “attack angles” may diminish control and result in damage. Sandbags or wedges have been suggested as work stages, but fail to provide sufficient remedy. A spherical, rigid work stage does, however. Used in a “ball-and-socket” configuration, a work stage with a spherical base can be adjusted 180º around all axes. The specimen is partially embedded in carbowax or cyclododecane in a small tray attached to a flattened surface of the spherical work stage. The stage is then placed in a “socket” or circular hole of appropriate diameter and held in position with one hand, the pin vise in the other. Commercial variations of this design (called engraving block vises or ball vises) are available for purchase but are expensive. Effective and inexpensive homemade models can be manufactured from any hard sphere (like a solid resin Bocce ball or large steel bearing ball) having a diameter of 2.5-3.5 inches. The ball can be rotated and turned easily to provide an infinite number of specimen positions and angles relative to the microscope and the preparator’s favored hand position, and the rigid work stage allows sharp focus to be maintained during preparation.

Cyclododecane as a temporary sealer and filler in molding specimens with porous and penetrable surfaces

by Gregory Brown

SVP 2006

One of the exceptional properties of silicone RTV molding compounds is their ability to flow and thereby capture and... more One of the exceptional properties of silicone RTV molding compounds is their ability to flow and thereby capture and reproduce extreme detail from the object being molded. One of their less admirable properties is their somewhat limited tear-strength. When these two properties meet on a specimen with deep cracks, open sutures, exposed cancellous bone or remnant porous matrix, there can be grave results. RTV may flow into these areas, penetrate the specimen deeply and tear during de-molding, ruining not only the mold but the specimen as well. Residual silicone RTV is impossible to remove from these deep interstices without damaging the specimen. There are several traditional methods of preventing unwanted penetration of RTV into these areas, but each has its own shortcomings. Clay and wax fillers are themselves difficult to remove, especially from very narrow sutures and cracks, as are thick consolidants from porous areas. Using a thixotropic (non-flowing) RTV may result in less detail-capture and a greater risk of mold flaws from air-entrapment. Choosing a molding compound with higher tear-strength could result in specimen failure rather than mold failure during de-molding. Cyclododecane (C12H24) is waxy hydrocarbon that sublimates completely over time at room temperature. This property makes it extremely useful as a temporary filler and consolidant. Applied as a melt, it provides a very effective fill or seal to penetrable or porous areas of specimens, and then simply disappears after de-molding. A case study of molding an exquisitely preserved juvenile Castoroides skull recently donated to the museum readily demonstrates the tools, techniques and benefits of using cyclododecane as a conservationally-sound temporary filler/sealant, allowing us to take full advantage of RTV properties to produce high-resolution, high-quality molds while minimizing risk to the specimen.

Molding and Casting of In-situ Articulated Skeletons in Soft Matrix: A Case Study from the Ashfall Fossil Beds, Nebraska

by Gregory Brown

2005, Society of Vertebrate Paleontology

Due in part to their excellent release properties and variable viscosities, modern silicone molding materials have... more Due in part to their excellent release properties and variable viscosities, modern silicone molding materials have greatly simplified the process of molding and casting well-preserved fossil specimens in the laboratory. Porous bone and, in particular, bone still partially embedded in a soft and porous matrix, however, still present serious challenges to successful molding. In addition, uncontrolled environmental conditions, lack of access to standard laboratory equipment, and unique conservation concerns multiply these challenges significantly when molding specimens remaining is-situ. In 2004, we began a project to mold several complete, articulated Clarendonian rhino (Teleoceras) and horse (Cormohipparion) skeletons preserved in-situ in soft volcanic ash at the Ashfall Fossil Beds near Orchard/Royal, Nebraska. Although the overall design of the one-piece molds is relatively straightforward, achieving a flawless mold and assuring safe, stress-free demolding in this situation requires subtle but important variations to our standard molding procedures including: 1) the use of cyclododecane to seal porous matrix and bone, 2) control of molding compound viscosities using fumed silica rather than liquid thixotropic additives, 3) incorporation of fabric reinforcement into mold perimeter, and 4) choice of addition-cure, platinum-catalyzed silicone RTV molding compound for its superior release properties, long mold life, and chemical resistance. During casting, the use of talc-extended polyester resin provides an ideal consistency for brush application and results in a high-resolution bubble-free cast that readily accepts acrylic paints and stains. Maintaining substrate and specimen integrity while minimizing alterative chemical treatments is an important goal in all molding projects, but is essential to the long-term survival of specimens being maintained in-situ under minimal environmental control.

Cyclododecane: Vanishing support for the preparation laboratory

by Gregory Brown

Brown, Gregory W., SVP 2004

The sodium hypochlorite solution for removing lichen from vertebrate track surfaces.

by Lisa Buckley

The removal of extraneous biological materials from vertebrate
ichnological specimens may be necessary if they... more The removal of extraneous biological materials from vertebrate
ichnological specimens may be necessary if they have been exposed to subaerial processes in the field for long periods of time. It is not uncommon for fossil track specimens to be found nearly completely covered with lichen colonies, especially those recovered from alpine areas. This paper describes a technique using a sodium hypochlorite solution (bleach) to remove lichen from a track surface containing numerous avian prints and small theropod prints with skin impressions.