Vertebrate Fossil Conservation

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.

Comparing gap- fillers used in conserving sub-fossil material.

by Nigel Larkin

By Nigel Larkin & Elena Makridou, published in The Geological Curator: GCG, Vol 7, no 2, 1999, 81-90.

Often when conserving mechanically weak sub-fossil bone material, an inert volumising filler for a chosen adhesive... more Often when conserving mechanically weak sub-fossil bone material, an inert volumising filler for a chosen adhesive (e.g. Paraloid B72) is needed to create a gap-filling substance to strengthen some bone, so as to reduce the potential of damage to some of the more fragile specimens. Although a frequent method, little is in print on this subject. Testing determined the comparative suitability of five materials (calcium carbonate, glass beads, crushed glass, glass bubbles and phenolic microballoons) as polymer fillers in terms of strength, shrinkage, reversability, ease of use, and adhesive properties at various filler t resin ratios. Glass beads (44 microns average diameter) at a ratio of 3:1 filler to resin by weight out-performed the other fillers in most of the categories.

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.

Pyrite Decay: cause and effect, prevention and cure

by Nigel Larkin

By Nigel R. Larkin. In: NatSCA News (Natural Sciences Collections Association), Issue 21, August 2011, p 35-43. ISSN No. 1741-3974.

Pyrite (FeS2) is a common mineral found in igneous, sedimentary and metamorphic rocks; it may be present
in... more Pyrite (FeS2) is a common mineral found in igneous, sedimentary and metamorphic rocks; it may be present
in petrology, mineral and palaeontological collections. Pyrite decay, or pyrite oxidation, has been recorded since the 19th century and various methods have been devised over the years to prevent or ’cure’ it with varying degrees of success. Methods of identifying pyrite decay in collections are discussed along with potential problems this can cause to the specimens and associated labels. Up to date prevention methods are discussed, including microclimates, controlled environments, collections surveys and resin coatings. Modern techniques of ‘curing’ pyrite are discussed in detail, including ammonium gas treatment and Ethanolamine Thioglycollate treatment.

Lessons from the Lagerstätte: An Ashfall Fossil Beds Retrospective and Update

by Gregory Brown

Brown, Gregory W., 2008. Program and Abstracts, Fossil Preparation and Collections Symposium, Petrified Forest National Park

Ashfall Fossil Beds in northeast Nebraska is a Miocene (Clarendonian) waterhole death assemblage containing fully... more Ashfall Fossil Beds in northeast Nebraska is a Miocene (Clarendonian) waterhole death assemblage containing fully articulated and associated skeletons of rhinoceroses, horses, camels, musk deer, birds and turtles preserved in death positions in volcanic ash. Subsequent to Ashfall’s discovery in 1972, some of the fossils were excavated and removed to the Museum collections (1977-1979), some partially excavated and reburied (1988-1990), and others exposed, prepared in-situ and left in place under the protection of the “Rhino Barn”, a structure providing limited control of environmental agents of deterioration (1991-2008). This thirty-year “experiment” has allowed us to observe differing modes and rates of deterioration and compare the efficacy of preservation strategies under various conditions. Collections made during the 1977-1979 field seasons, now housed in the University of Nebraska State Museum, present their own unique challenges. Approximately three thousand field jackets containing the remains of hundreds of individual skeletons were collected during this period. Each jacket was separately numbered and mapped and each contained perhaps only a part of a single articulated skeleton, or, more typically, parts of multiple skeletons of multiple taxa, associated elements and isolated elements, many of which were revealed only after preparation and thus not referenced in the field notes. Traditional collection databases such as Specify are incapable of tracking such complex associations of specimens or facilitating their full curation. Prior to a recent move and reorganization of these collections, we designed an inventory-based relational database capable of tracking all “objects” within the collection, regardless of their curatorial status, location or known associations. This database relates field notes, inventory observations, curator’s notes and catalogue records and is an essential tool in re-uniting individuals that had become dissociated during collection, preparation and years of research. In addition, newly designed, stable support systems were constructed for skulls and other heavy, fragile elements to improve storage and assure safe handling. Construction of a new, much larger “Rhino Barn” will begin in 2008, allowing excavation, in-situ preservation and research to continue for many years to come.

Conservation Principles Applied to Paleontology Collections.

by Gregory Brown

Brown, Gregory W., 2009 SVP Adhesives and Consolidants Professional Development Workshop, Bristol, England

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.

A Conservation Approach to the Preservation of In-Situ Fossil Sites: A Case Study of the Ashfall Fossil Beds in Nebraska, USA

by Gregory Brown

Brown, Gregory W., 2011. II Conservation Workshop, The Institut Català de Paleontologia Miquel Crusafont, Sabadell, Spain (1.5 hour invited presentation)

Attempting to preserve and maintain vertebrate fossils in-situ is becoming a more common strategy in efforts to... more Attempting to preserve and maintain vertebrate fossils in-situ is becoming a more common strategy in efforts to provide increasingly meaningful educational experiences for the public. In-situ preservation also provides research paleontologists an opportunity to preserve details of stratigraphy, taphonomy, associations and other data that might otherwise be lost using normal collecting techniques. Maintaining a collection of vertebrate fossils in-situ, however, is not an easy task. Unlike traditional collections housed in the “closed system” environments of museums, an in-situ collection is an “open system”; we cannot control every aspect of the environment. The infinite variety of climate, sediment type, chemistry and mode of bone preservation and the complex interactions between them combine to create difficult and often unanticipated problems. Rather than finding a perfect solution, we must often implement an imperfect compromise. Of the agents of deterioration that we normally encounter, by far the most problematic is moisture; in one form or another, it is a major component of every process responsible for the deterioration of fossils in-situ.
Ashfall Fossil Beds State Historical Park in Northeast Nebraska, USA, was developed to preserve a community of Miocene animals that were killed, buried and preserved in volcanic ash from a major volcanic eruption about 1700 km to the west in Idaho, USA. Hundreds or rhinoceros, three-toed horses, camels, saber-tooth deer and other animals are perfectly preserved in their death positions. Since the park’s opening in 1990, our in-situ preservation strategy at Ashfall has evolved each year as we gain experience from our prior attempts to control exposure, temperature, humidity, biological agents and physical integrity of the matrix. It must be emphasized that solutions that have been effective at Ashfall may not apply to other sites. Each site is unique, and the best strategies for preservation are likewise unique. An effective preservation strategy requires a systematic approach relying predominantly upon the principles of preventative conservation (recognizing the agents of deterioration and minimizing their effects) and secondarily upon limited remedial conservation which may include application of appropriate consolidants. The decision to use any consolidant, however, is not a trivial one.
This session will include a presentation but also relies on audience participation. Questions, comments, suggestions, and personal experiences with in-situ preservation are welcome.

When the cradle rocks: Simple strategies for the stable storage and safe use of paleontological collections

by Gregory Brown

SVP

Limiting the potential for damage to any museum object involves addressing all of the “agents of deterioration”... more Limiting the potential for damage to any museum object involves addressing all of the “agents of deterioration” recognized by conservators, but the vast majority of damage to paleontological collection objects can be attributed to a single agent: direct physical forces (gravity and applied forces) related to improper storage and handling. An irregular object placed on a flat surface exerts all of its mass on three points, imparting considerable stress to the object. If the majority of mass is born on only two of these points, the object will be both under stress and unstable (prone to motion). It is a mistake to assume that seemingly sound and robust specimens do not require proper support. For larger objects, traditional form-fitting cradles of reinforced plaster or resin relieve stress by distributing an object’s mass over an infinite number of points, however the irregular cradle itself may not assume a preferred orientation or stable resting position in storage. Addition of a cradle support system composed of blocks of expanded polyethylene foam on a rigid base of high-density Masonite provides cradle stability and isolation from vibration. Smaller objects benefit from simple polyethylene foam cradles. Proper orientation and compartmentalization in cabinet drawers limits destructive motion. It is also a mistake to assume that those who utilize our collections have the requisite skill or common sense to handle specimens safely. Formal written protocols should be provided that detail both basic and specialized handling guidelines and requirements. In addition, wise choice of primary storage orientation and use of “clam-shell” cradles can significantly lessen the need for direct handling of specimens. Well-designed storage can be both aesthetically and functionally elegant and, when combined with enforced handling protocols, can greatly reduce the forces that commonly damage our collections.

Fossils with little relief: Using Lasers to conserve, image, and analyze the Ediacara biota

by Jonathan Antcliffe

The Smithsonian Institution's Exhibit Fossil Preparation Lab Volunteer Training Programme Part I: Design and Recruitment

by Matthew Brown

Steve Jabo, Abby Telfer, Matthew A. Brown, Peter Reser, Matthew E. Smith, and Michael Holland

The Smithsonian Institution, through a grant from the Smithsonian Women's
Committee, implemented a programme... more The Smithsonian Institution, through a grant from the Smithsonian Women's
Committee, implemented a programme during the fall and winter of 2008 to teach
the basics of mechanical fossil preparation, moulding and casting to individuals
seeking to work as volunteer preparators in the National Museum of Natural
History's exhibit preparation lab, called FossiLab. Four outside preparators were
contracted to conduct the instruction; two instructors taught two five-day sessions
on molding and casting and two other instructors taught two six-day sessions on
preparation. The Department of Paleobiology's (Paleobiology) curatorial staff
instructed the groups in paleobotanical preparation and microfossil processing and
picking. All instruction took place in FossiLab during public hours.
Registration for the programme was conducted via the department's web page where
a detailed description of the work and the lab familiarized prospective students with
the type of work they would be performing. They were also asked a series of selfevaluative
questions in an attempt to filter out those who might not have the innate
motor skills or temperament needed for the job. Those who were confident in their
decision to volunteer were interviewed in FossiLab, and the majority of those then
registered for the programme.
Twenty nine people, some new and some experienced, were trained. FossiLab is
now staffed each day by as many as six volunteer preparators who perform a variety
of tasks for Paleobiology. The number of weekly person-hours has tripled since
the training. Continued, focused training on individual projects is carried on by the
Vertebrate Paleontology Preparation Laboratory staff. Eighteen hours of videotape
was recorded during the training and will be edited and made available via DVD and
the internet.

The Smithsonian Institution's Exhibit Fossil Preparation Lab Volunteer Training Programme Part II: Training And Evaluating Student Preparators

by Matthew Brown

Matthew Brown, Matthew Smith, Steve Jabo, and Abby Telfer

In November and December of 2008, the National Museum of Natural History
hosted a training course for instruction... more In November and December of 2008, the National Museum of Natural History
hosted a training course for instruction of paleontological preparation methods in
order to build a large pool of volunteers for the FossiLab public exhibition.
Through a grant from the Smithsonian Women's Committee, the Department of
Paleobiology funded four weeks of intensive, hands-on training for a group of 29
volunteers in moulding, casting and fossil preparation methods. Contracted instructors
worked with institutional staff to create a curriculum for training specific tasks,
as well as to create general knowledge of preparation methods. Classes consisted
of lecture, demonstration, and hands-on components. Instructors monitored the students
throughout the instruction period, and concluded the programme with written
and practical examinations. The instructors provided written evaluations for each
student and presented recommendations for placement with specific tasks within
the department. After the conclusion of the programme students retained much of
their instruction and have gone on to successfully keep the preparation laboratory
staffed while preparing fossils for the visiting public.

THREE DIMENSIONAL PREPARATION OF A LATE CRETACEOUS STURGEON FROM MONTANA: A CASE STUDY

by Matthew Brown

Constance Van Beek and Matthew A. Brown

Thorough description of an exceptionally well-preserved fossil sturgeon required
nearly complete disarticulation... more Thorough description of an exceptionally well-preserved fossil sturgeon required
nearly complete disarticulation of much of the skull, as well as preparation of fins
and other very delicate structures. Preparation took place in distinct stages in order
to allow for detailed photographic documentation of the structure and relationship of
individual bones before they were disassociated from the skeleton. Prior preparation
and application of materials presented challenges to cleaning of surfaces that were
overcome using a combination of chemical and gentle mechanical preparation methods.
Combinations of consolidants were experimented with until a method for stabilization
for fragile parts of the skeleton was decided upon. Extreme care was
required during disarticulation of the very delicate elements, and a storage method
was devised to maintain relationships of individual bones after removal from the
skull. Justification was made based on research needs to sacrifice certain aspects of
conservation principles in selection of non-reversible adhesives and consolidants for
stabilization, repair, and reconstruction.

THE USE OF CYCLODODECANE TO PROTECT DELICATE FOSSILS DURING TRANSPORTATION

by Matthew Brown

Co-authored with Amy Davidson, Journal of Vertebrate Paleontology, 2010