Table 1.
Geological age and depositional setting of study specimens.
| geological age | specimen (taxon, element) | taphonomic setting | preservation observations | collagenase reactivity | relevant publications |
|---|---|---|---|---|---|
| Recent (ca 9 months to 1.5 years post-mortem) | ostrich (Struthio camelus), femur, tibia | 5 days natural degradation, stored with desiccant | collagen intact; vessels, osteocytes present | + | Schweitzer et al. 2005a,b |
| Recent (ca 2–3 years post-mortem) | emu (Dromaius novaehollandiae), femur, tibia | buried 2 years, exhumed | collagen intact; vessels, osteocytes present | + | Schweitzer et al. 2005b |
| Recent (14+ years post-mortem) | ostrich (Struthio camelus), femur | −20oC storage ca 2 years, then at room temperature for ca 12 years, untreated | collagen intact; vessels, osteocytes present | + | Schweitzer et al. 2005a |
| Recent (800–1200 years) | moa (MOR-OFT255), proximal femur | cave deposits, New Zealand | collagen intact, pigmented; vessels, osteocytes present | + | n.a. |
| Recent (ca 1000 years) | bison (Bison bison), rib | exposed and weathered | collagen intact, pigmented; vessels, osteocytes present | + | n.a. |
| Holocene (ca 12 ka) | mammoth (Mammuthus columbi) (MOR 91.72), femur | aeolian silt or loess, underlying palaeosols | fibrous collagen tunnelled and degraded; no visible osteocytes or vessels | + | n.a. |
| Pleistocene (ca 300 ka) | mammoth (Mammuthus columbi) (MOR 604), skull | Eastern Montana, Doeden gravel beds, fluvial, river sands | collagen thin, fibrous, vessels and osteocytes pigmented | + | Hill & Schweitzer 1999; Schweitzer et al. 2002 |
| Late Pleistocene (ca 300 ka) | mastodon (Mammut americanum) (MOR 605), rib | Eastern Montana, Doeden gravel beds, fluvial, river sands | collagen fragmented, fibrous, abundant nucleated osteocytes | + | Hill 1998 |
| Pliocene (2 Ma) | manatee (Trichechidae spp.) (UF123664), rib | depositional environment not known | matrix creamy, no vessels, cells free-floating, fragmented | n.a. | n.a. |
| Late Miocene–Early Pliocene (2.0–14.0 Myr) | whale (cf. Balaenoptera) (WCBa-20), vertebra | Pisco Formation, Peru; marine, diatomaceous silt and tuffaceous mudstone; articulated, some apparent baleen | matrix creamy, no vessels, cells present but fragmented | n.a. | Esperante-Caamano et al. 2002; Brand 2003, 2004; Esperante 2002 |
| Early Miocene (23.5–5 Myr) | Megoeodon grandis (MOR 396), phalanx | siltstone deposit | little dissolution of mineral in EDTA; isolated crystalline vessels, no cells | n.a. | n.a. |
| Late Cretaceous, Maastrichtian (66.5–67.0 Myr) | Tyrannosaurus rex (MOR 555), tibia | Hell Creek Formation, Eastern Montana; fluvial–overbank; consolidated white sandstone mixed with fine-grained mud and plant material; articulated, approximately 90% complete | matrix preservation variable, vessels and osteocytes present; vessels flexible, or crystalline; some bone fragments resist EDTA demineralization | − | Schweitzer et al. 1997a,b, 1999a,b; Horner & Padian 2004, 2005a |
| Late Cretaceous, Maastrichtian (66.5–67.0 Myr) | Tyrannosaurus rex (MOR 1128), associated fragments | Hell Creek Formation, Eastern Montana; mudstone/overbank | no visible dissolution of mineral, no soft tissue recovered | n.a. | Horner & Padian 2004 |
| Late Cretaceous, Maastrichtian (66.5–67.0 Myr) | Tyrannosaurus rex (FMNH-PR-2081), associated fragments | Hell Creek Formation, fluvial/point bar; loosely consolidated sandstone with Unio, freshwater snail, gar, turtle, some elements encrusted in pyrite | variable recovery of soft tissue, sheet-like matrix and flexible vessels, osteocytes; some crystalline elements resist demineralization | − | Brochu 2003; Erickson et al. 2004; Erickson 2005; Schweitzer et al. 2005a |
| Late Cretaceous, Maastrichtian (66.5–67.0 Myr) | Tyrannosaurus rex (BHI 3033), associated fragments | fluvial/point bar, seasonally dry; bones weathered, well-preserved plant material associated | no visible dissolution of mineral, no soft tissue recovered | n.a. | n.a. |
| Late Cretaceous, Maastrichtian (66.5 Ma) | Triceratops horridus (MOR 699), juvenile, rib | Hell Creek Formation, Eastern Montana; fluvial/channel sandstone; skull, associated elements, ribs | soft tissues rare, sheet-like matrix, flexible vessels, osteocytes present | − | n.a. |
| Late Cretaceous, Maastrichtian (68–70 Myr) | Tyrannosaurus rex (MOR 1125), femur | Hell Creek Formation, Eastern Montana; fluvial/estuarine, associated skeletal elements, skull and limbs | sheet-like matrix, vessels flexible, osteocytes with long filipodia | − | Horner & Padian 2004; Schweitzer et al. 2005a |
| Late Cretaceous, Maastrichtian (68–70 Myr) | Madagascar theropod (UA 9044), rib | Maevarano Formation in Mahajanga Basin, fine grained debris flow, sandstone dominating with some muds intermixed | matrix creamy, transparent flexible vessels; plant/fungal contamination in vessels; no osteocytes observed | n.a. | Rogers et al. 2000; Rogers 2005 |
| Early Cretaceous, Albian (92–108 Myr) | Santana theropod (MN 4802-V), associated fragment | depositional conditions unknown | very small remnant of flexible matrix after demineralization | n.a. | Kellner 1996 |
| Early Campanian (78 Ma) | Brachylophosaur canadensis (MOR 794), associated fragments | Lower Judith River Formation; medium-grain sandstone; articulated, virtually complete; skin impressions in surrounding sediments | variable preservation of matrix, vessels and osteocytes, mostly crystalline morphs, rarely flexible tissue | n.a. | Harmon 1997; Adams & Organ 2005; Prieto-Marquez 2005 |
| Triassic (ca 200 Ma) | dicynodont (NCSM 21719), femur | North Carolina, not in situ; medium/coarse-grained sands; partially articulated limb | dissolved completely in EDTA; no soft tissue recovered | n.a. | Green et al. 2005 |