TABLE 1. List of the sampled sauropod specimens at the Howe-Stephens and Howe Scott quarries, with taxon assignment (based on field observations and later revised after Tschopp et al., 2015), measurements, bone tissue types, HOS and BOS, RS, number of cycles, presence of an EFS, and the bone surface conditions (OS = original surface, NOS = not original surface). Note that the bone tissue type usually consists of two letters; the first one representing the main bone tissue type that is present in the cortex, and the second one only within the innermost or outermost cortex (Table 3). Bone length is here defined as the largest proximal-distal distance within each bone. Both bone width and bone thickness have been taken at the sampling location at the mid-diaphysis. Due to poor preservation, the tibia of SMA 0007 “XL” could not be identified as a left or right tibia. Note that bone width and bone thickness for SMA 0015 “David” tibia and SMA G50/91-1 could not be measured since the bones remained in a plaster jacket and were only partially uncovered for sampling. Femur (l) SMA 0011 “Max”, drilled posterior, was sampled by PMS in 2001, when the bone was in preparation; femur (l) SMA 0011 “Max”, drilled anteriorly was sampled by KW in 2014, when the bone was no longer in the plaster jacket. The inaccuracies caused by partial coverage by plaster jackets is illustrated by the ~ symbol. Bone width and bone thickness were not measured for the SMA 0087 “Chris” femur (r), as well as the bone thickness for SMA M16/12-3, since the bones were still covered in a plaster jacket during sampling.
| Specimen designation | Taxon | State of preservation | Sampled bone | Bone length (mm) | Bone width (mm) | Bone thickness (mm) | Bone tissue type | HOS | BOS | RS | Cycles | EFS and bone surface |
| Howe-Stephens Quarry | ||||||||||||
| SMA 0002 “E.T.” | Camarasaurus lewisi | Articulated skeleton | Humerus (r) | 705 | 120 | 82 | G | 13 | Adult III | RS 7 | 0 | Yes, NOS |
| Femur (l) | 935 | 175 | 85 | F/E | 11 | Adult II | RS 2 | 3 | Yes, OS | |||
| Tibia (l) | 615 | 110 | 60 | F/EFS | 12 | Adult II to adult III | RS 3 | 9 | Yes, OS | |||
| SMA 0007 “XL” | Galeamopus sp. | Disarticulated skeleton | Humerus (r) | 925 | 160 | 95 | E/F | 10 | Adult I to adult II | RS 3 | 8 | No, OS |
| Ulna (l) | 745 | 100 | 80 | F/EFS | 12 | Adult II to adult III | RS 5 | 4 | Yes, NOS | |||
| Tibia (?) | 980 | 120 | 95 | F/E | 11 | Adult II | RS 4 | 3 | Yes, NOS | |||
| SMA 0015 “David” | Diplodocinae indet. | Articulated specimen | Femur (l) | 1340 | 210 | 95 | E/F | 10 | Adult I to Adult II | RS 2 | 4 | No, NOS |
| Tibia (l) | 1010 | - | - | F/E | 11 | Adult II | RS 4 | 1 | Just started, NOS | |||
| Fibula (l) | 1040 | 80 | 65 | F/E | 11 | Adult II | RS 4 | 7 | Yes, NOS | |||
| SMA G46/87-1 | Diplodocinae indet. | Isolated bone | Humerus (l) | 715 | 140 | 75 | D/E | 8 | Sexual Maturity | RS 1 | 8 | No, NOS |
| SMA G50/91-1 | Diplodocinae indet. | Isolated bone | Humerus (r) | 735 | _ | _ | D/E | 8 | Adult I | RS 2 | 9 | No, NOS |
| SMA G47/87-1 | Diplodocinae indet. | Isolated bone | Femur (l) | 1200 | 175 | 75 | E/D | 9 | Sexual Maturity | RS 1 | 0 | No, NOS |
| Howe Scott Quarry | ||||||||||||
| SMA 0014 “Jacques” | Apatosaurus louisae | Articulated specimen | Femur (r) ant. section | 1640 | 295 | 110 | E/D | 9 | Adult I | RS 3 | 18 | No, NOS |
| Femur (r) post. section | 1640 | 295 | 110 | E/D | 9 | Adult I | RS 3 | 18 | No, NOS | |||
| Tibia (r) | 640 | 175 | 115 | E/F | 10 | Adult I to Adult II | RS 4 | 9 | No, OS | |||
| SMA 0011 “Max” | Galeamopus sp. | Associated specimen | Humerus (r) | 900 | 190 | 80 | D/E | 8 | Sexual Maturity | RS 1 | 10 | No, OS |
| Humerus (l) | 850 | 180 | 90 | D/E | 8 | Sexual Maturity | RS 1 | 8 | No, NOS | |||
| Ulna (l) | 635 | 95 | 65 | E/F | 10 | Adult I to Adult II | RS 3 | 10 | No, OS | |||
| Radius (l) | 620 | 100 | 65 | E/F | 10 | Adult I to Adult II | RS 3 | 11 | No, OS | |||
| Femur (l) ant. section | 1490 | 240 | 145 | D/E | 8 | Sexual Maturity | RS 1 | 13 | No, OS | |||
| Femur (l) post. section | 1490 | 240 | 145 | D/E | 8 | Sexual Maturity | RS 1 | 11 | No, NOS | |||
| Tibia (l) | 870 | 80 | 140 | E/D | 9 | Adult I | RS 3 | 9 | No, OS | |||
| Fibula (l) | 870 | 90 | 60 | E/D | 9 | Adult I | RS 3 | 8 | No, OS | |||
| SMA M16/12-3 | Diplodocinae indet. ? | Isolated bone | Femur (l) | 1250 | 225 | - | F/E | 11 | Adult II | RS 3 | 2 | Yes, NOS |
| SMA 0084 “Rich” | Diplodocinae n. gen. et n. sp. | Articulated specimen | Tibia (l) | 725 | 135 | 80 | G | 13 | Adult III | RS 7 | 1 | Yes, NOS |
| Fibula (l) | 800 | 80 | 50 | G | 13 | Adult III | RS 7 | 0 | Yes, NOS | |||
| SMA 0087 “Chris” | Diplodocinae n. gen. et n. sp. | Articulated specimen | Femur (r) | 1440 | - | - | E/F | 10 | Adult I | RS 2 | 6 | Yes, NOS |
| Tibia (r) | 750 | 140 | ~110 | G | 13 | Adult III | RS 7 | 2 | Yes, NOS | |||
| Fibula (r) | 800 | 100 | ~70 | G | 13 | Adult III | RS 7 | 0 | Yes, NOS | |||
TABLE 2. Description of the seven bone tissue types A-G occuring in the cortices of sauropod long bones (after Klein and Sander, 2008).
| Bone tissue type | Bone organization | Vascular canal organization | Primary osteons | Secondary osteons | Growth marks and EFS | ||||
| A | Non-laminar | - | - | - | - | ||||
| B | Woven fibrolamellar bone | Mostly longitudinal, high density | - | - | - | ||||
| C | Laminar fibrolamellar | Mostly circumferential, less dense than in tissue B | Starting to form, lamellar bone lining starts to form | - | - | ||||
| D | Laminar fibrolamellar | Mostly laminar, less dense than in tissue C | Present, increase in lamellar bone lining | Large, open (“young”) | - | ||||
| E | Laminar fibrolamellar | Mostly laminar, less dense than in tissue D | Distinctive, increase in lamellar bone lining | Denser than in tissue E, remodeling up to middle of primary cortex | May rarely occur | ||||
| F | Laminar fibrolamellar | Mostly laminar, clear decrease in density | Distinctive, nearly completely filled by lamellar bone | Dense, distinctive, remodeling up to two-thirds of primary bone | Both may be present | ||||
| G | Haversian | If present, mostly laminar | If present, distinctive | Dense, distinctive, nearly completely remodeled primary cortex | Both present | ||||
TABLE 3. The 13 HOS and their correlated BOS, with the seven bone tissue types (after Klein and Sander 2008; Sander et al. 2011b).
| Bone tissue type | HOS | BOS |
| Type A | HOS 1 | Embryo |
| Primarily type A, with type B in outer cortex | HOS 2 | Embryo to Hatchling |
| Primarily type B, with type A in inner cortex | HOS 3 | Hatchling |
| Primarily type B, with type C in outer cortex | HOS 4 | Hatchling to Juvenile |
| Primarily type C, with type B in inner cortex | HOS 5 | Juvenile |
| Primarily type C, with type D in outer cortex | HOS 6 | Juvenile to Subadult |
| Primarily type D, with type C in inner cortex | HOS 7 | Subadult |
| Primarily type D, with type E in outer cortex | HOS 8 | Sexual Maturity |
| Primarily type E, with type D in inner cortex | HOS 9 | Adult I |
| Primarily type E, with type F in outer cortex | HOS 10 | Adult I to Adult II |
| Primarily type F, with type E in inner cortex | HOS 11 | Adult II |
| Primarily type F, with EFS in outer cortex | HOS 12 | Adult II to Adult III |
| Type G | HOS 13 | Adult III |
TABLE 4. Remodeling Stages (RS), based on the maximum number of generations of secondary osteons in the inner, middle, and outer cortex (after Mitchell et al. 2017).
| Generations of secondary osteons | RS | ||
| Inner cortex | Middle cortex | Outer cortex | |
| 0 | 0 | 0 | 0 |
| 1 | 0 | 0 | 1 |
| 1 | 1 | 0 | 2 |
| 2 | 1 | 0 | 3 |
| 2 | 1 | 1 | 4 |
| 2 | 2 | 1 | 5 |
| 3 | 2 | 1 | 6 |
| 3 | 2 | 2 | 7 |
| 3 | 3 | 2 | 8 |
| 4 | 3 | 2 | 9 |
| 4 | 3 | 3 | 10 |
| 4 | 4 | 3 | 11 |
| 4-5 | 4 | 4 | 12 |
| 4-5 | 5 | 4 | 13 |
| 4-5 | 5 | 5 | 14 |
| 4-5 | 6 | 5 | 15 |
