Skeletal composition 1 and 2
These values refer to the ORIGINAL composition of the skeleton, not the preserved composition. For the latter, see "Replacement Minerals" on the Main Collections Form. The first entry should be the dominant composition, the second is reserved for secondary components, e.g., sponges that have siliceous and CaCO3 skeletal elements. Quotes indicate a value that should be used only if a more specific value cannot be determined. "Entirely soft tissue" refers to organisms such as jellyfish and flatworms. The calcite categories are divided this way:

• low Mg calcite: < 4 mole-% MgCO3
  
• intermediate Mg calcite: > 4, < 8 mole-% MgCO3
  
• high Mg calcite: => 8 mole-% MgCO3
  

Adult size
Check entire body if the size estimate pertains to the entire body instead of a part. Otherwise, enter the standardized name of the body part whose size is being described (e.g., "calyx"; "M1"; "leaf"). Provide size information using the millimeter categories in the pull-down menus for length, width, height, area, or volume. For example, for volume, an organism that is .03 mm on a side would be in the smallest category and a whale 30 m x 5m x 5m would be in the >10^8 to < 10^9 category. Applies to measures of whole body size, e.g., maximum axial length or other maximum dimension, maximum area of plan view projection, volume calculated as length x width x height.

Leaf size categories translate as follows (based on placements of geometric means):

Leaf category	Minimum area	PBDB area category
Leptophyll	< 25 mm^2	1.0 to < 10 mm^2
Nanophyll	> 25 mm^2	10 to < 100 mm^2
Microphyll	> 225 mm^2	100 to < 1000 mm^2
Notophyll	> 2025 mm^2	1000 to < 10^4 mm^2
Mesophyll	> 4500 mm^2	1000 to < 10^4 mm^2
Macrophyll	> 18225 mm^2	10^4 to < 10^5 mm^2
Megaphyll	> 164025 mm^2	10^5 to < 10^6 mm^2

*Relative thickness
Thick versus intermediate versus thin. Refer to visual images to judge this character. Thick shells have a high ratio of overall (average) thickness relative to body size, thin shells have a low ratio of thickness relative to body size.

*Internal skeletal architecture
This only applies to original architecture of biomineralized tissues. We regard brachiopod shells with punctae as porous. Bivalve and gastropod shells generally have compact skeletal tissue (watch for exceptions such as pycnodont oysters that display porous shell structure).

• Porous: Conspicuous voids within the skeletal tissues.
• Compact or Dense: Few or no voids within the skeletal tissues.

*3-D form
Overall shape of the taphonomically relevant major part (could be the whole organism). For bivalves, consider the shape of single valves, for brachiopods, use shape of both valves together. This is justified on the basis of which components of the organisms are typically subjected to the majority of taphonomic processes. The categories can be defined geometrically in terms of maximum length (X), width (Y), and height, which can be about the same (~), unequal (>), or very unequal (>>). Geometrical definitions are given in brackets. (Note that the following terms were formulated for use in Project 1 of the Taphonomy Working Group and may not be readily applicable to organisms other than bivalves, gastropods, and brachiopods.)

• Sheet: sheet-like, one dimension very short relative to the other two, e.g., Pinna, Pecten, strophomenid brachiopods (Schizophoria), Lingula, oxycone ammonites [X ~ Y >> Z]
• Blade: flat and elongate, one dimension significantly longer than the others, e.g., razor clam (Ensis, Siliqua) [X >> Y > Z]
• Inflated sheet: flattened, hemispherical shells as in Cerastoderma, most ammonites [X ~ Y > Z]
• Inflated blade: elongate, curved valves, as in mussels [X > Y > Z]
• Roller-shaped: cylinder, e.g., high-spired gastropods such as Turritella, crinoid with stem [X > Y ~ Z]
• Spherical: all 3 axes similar in length, e.g., Natica (moon snail), Terebratula, blastoid calyx [X ~ Y ~ Z]

*Skeletal reinforcement
This is meant to apply to features of shells but could also pertain to leaves, scutes, carapaces. If shell is smooth and lacks skeletal reinforcements, check this box "smooth" and ignore pull-down menus for skeletal reinforcement features. Options for each pull-down menu are major, minor, absent. Major features are comparable to or greater than the thickness of the shell and should cover a notable portion of the shell. Minor features are less than the shell thickness and cover small areas of the shells. (Note that the following terms were formulated for use in Project 1 of the Taphonomy Working Group and may not be readily applicable to organisms other than bivalves, gastropods, and brachiopods.)

• None (smooth): even surface (except for growth banding), lacking ribs, spines and folds.
• Folds: plications, undulations or other folds in shell surface as in Spirifer, involves whole shell; thickness remains consistent across folds.
• Ribbing: repeated, thickened, raised structures on shell surfaces. Thickenings can be either radial, comarginal, axial or spiral.
• Spines (or spine bases): pointed, typically elongate appendages on shell surfaces.
• Internal supports: as in sand dollar buttresses and ammonite, anthozoan, bryozoan, and archaeocyathid septae

Adult polymorphism/dimorphism?
Applies to distinctive dimorphs or polymorphs that reflect sexual dimorphism or other morphological variation in adults due to possible causes such as population density, temperature, nutrient supply, and other external environmental factors. This does not relate to normal phenotypic variation in a population.

Ontogeny
The different ways that organisms can grow into adults. Accretion applies to body types that grow incrementally, as in bivalves and solitary corals. Both molting and addition of parts applies to arthropods. Plants grow both by accretion and by addition of parts. Modification of parts and accretion applies to vertebrates. Includes astogeny of colonial organisms, and for these check "addition of parts" in addition to any other appropriate boxes.

Social grouping
Designates the dominant type of social organization among individuals in a population. Colonial organisms are physically attached to each other in a structural framework, e.g., bryozoans, corals. Social insects and oyster banks should be classified as gregarious rather than colonial.

Clonal
Enter yes if individuals can develop from pre-existing individuals without sexual reproduction. All prokaryotes, some aphids, some beetles, and some plants are clonal; some corals and bryozoans can produce clones.

General environment
Characterizes the overall life habitat of adult individuals of the taxon.

Locomotion
Characterizes the dominant locomotory capabilities of adults. Stationary refers to fixed in place without capability of changing location (relation to substrate), e.g., vascular plants, corals, bryozoa, barnacles, oysters. Facultatively mobile organisms can change location but do so infrequently, e.g., crinoids, some infaunal bivalves. Floating organisms and epibionts on living mobile organisms are passively mobile. Organisms that move habitually, of their own volition, are actively mobile.

Attached?
Is the adult organism attached to a substrate?

Epibiont?
Is the organism an epibiont? Any organism that is attached to another organism during part of its life cycle is an epibiont.

Life habit
Descriptors for specific mode of animal life in relation to substrate and plant physiognomy. Upper blocks of terms refers to aquatic animals, second block to terrestrial vertebrates, and third block to plants.

• boring - excavations into hard substrate by unexciting organisms, e.g., endobionts
• infaunal - organism lives within unlithified (soft) substrate
• semi-infaunal - body of organism partly within substrate or may be covered by sediment during life
• epifaunal - during life, body positioned at or on the sediment-water interface or surface of other hard substratum (e.g., encrusters of live or dead skeletal material, attachers to rocky shores, epibionts that live on epifaunal organisms, etc.)
• nektobenthic - organism actively swims in water column when necessary; resident on seafloor at other times
• nektonic - free swimming organism within water column
• planktonic - free floating organism within water column (includes pseudo-plankton such as epibionts hitchhiking on floating debris or organisms)

• fossorial - organism burrows within terrestrial substrate for dwelling
• ground dwelling - organism spends most of time on ground surface (beasts with down-to-earth life style)
• arboreal - organism resides above ground surface within canopies of trees
• volant - organism relies on flight but may rest on/in ground or in trees.
• amphibious - organisms that frequent both terrestrial and aquatic environments

• herbaceous - non-woody plant, annual or perennial, that does not attain a tree-like habit
• arborescent - non-woody (e.g., palm tree) or woody perennial plant with branching system and canopy [get Halley, Tomlinson, ?? ref]
• aquatic - non-woody plant with the entire life cycle in water

Diet/feeding mode
The primary biological or physical source of energy for an organism. Not meant to include all active feeding strategies.

• chemoautotroph - bacteria, some bivalves (deep-sea vent faunas)
• "photoautotroph" - plants that cannot be assigned to more specific categories
• C3 autotroph - primarily shrubs, trees, herbs, ground-cover plants
• C4 autotroph - primarily grasses (<1% of present plant taxa)
• CAM autotrophy - euphorbs, some grasses, other oddballs (3-4% of present plant taxa)
• chemosymbiotic - bacteria
• photosymbiotic - organism harbors zooxanthellae algae
• herbivore - eats plants
• omnivore - eats plants and animals and other stuff; includes raspers and scrapers
• carnivore - eats living or dead animals, either by predation or scavenging
• parasite - relies on living host organism
• suspension feeder - acquires suspended particles from water column
• deposit feeder - acquires nutrients either by ingesting sediment or collecting organic matter from sediment
• detritivore - ingests dead organic material
• saprophage - plants that grow on or within other plants and reproduce without developing their own vegetative body
• coprophage - animals that live primarily on the feces of other organisms

Vision

• blind or very weak vision - includes the eyes of lower phyla where they are used for simple phototaxis towards or away from lighter regions of the environment. With eyespots (ocelli). Simple light receptors, which cannot form an image.
• limited range of vision - ranges from simple shadow effects to more complex eyes such as in gastropods and pectinid bivalves, with the ability to detect objects.
• well-developed vision - Well developed eyes that produce a good image of the world; e.g. most trilobites and many other arthropods as well as chephalopods.

Reproduction

• oviparous - egg-laying
• ovoviviparous - retains eggs within body until hatched
• viviparous - bears live young
• alternating - generations alternate between sexual and asexual stages
• homosporous - single type of spore produced
• heterosporous - male and female spore bearing
• seeds - fertile reproductive structures, without surrounding nutrient tissue
• fruits - nutrient tissues enclosing seeds

Asexual
Cloning or budding.

Brooding
Young retained internally after birth.

Dispersal (gametes)
What carries the gametes? This does NOT include clones. "Animal" includes pollen vectors.

Dispersal (larvae/seeds/juveniles)
What disperses the offspring? Does not include clones.

• planktonic - includes mangrove seeds, floating coconuts
• non-planktonic - larvae lacking planktonic phase of life cycle
• wind-dispersed
• animal-dispersed
• mobile - active self-dispersal at a large spatial scale; current-dispersed animal larvae don't count
• gravity - almost no dispersal; coconuts or other terrestrial objects that fall to the ground with a thump

*Note: These fields apply in particular to a project to assess taphonomic durability through the Phanerozoic for bivalves, gastropods, and brachiopods but may be used for other taxonomic groups where appropriate.