Table 2.
Ontogenetic allometry of thylacine long bones. Reduced major axis (RMA) analysis of allometric growth patterns of thylacine forelimb (humerus and radius) and hindlimb (femur and tibia) bones with comparisons to published marsupial [32,53] and placental [33] data. All four thylacine long bones scaled with positive allometry throughout ontogeny, similar to that seen in placental carnivores (i.e. Panthera tigris, Canis latrans), but dissimiar to growth rates observed in other marsupials and placental herbivores Cetartiodactyla. + positive allometry; − negative allometry; iso, isometry.
| humerus |
radius |
||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| taxon | n= | Y-int | slope | 95% CI limits | R2 | allometry | n= | Y-int | slope | 95% CI limits | R2 | allometry | ref |
| marsupials | |||||||||||||
| Thylacinus cynocephalus (Tasmanian tiger) | 13 | 0.648 | 1.198 | 1.154, 1.242 | 0.997 | + | 13 | 0.757 | 1.403 | 1.321, 1.486 | 0.992 | + | this study |
| Trichosurus Vulpecula (brushtail possum)a | 51 | nd | 0.887 | nd | 0.950 | − | 51 | nd | 0.780 | nd | 0.931 | − | [32] |
| Macropus eugenii (tammar wallaby)a | 25 | nd | 0.917 | nd | 0.957 | − | 24 | nd | 0.620 | nd | 0.945 | − | [32] |
| Monodelphis domestica (short-tailed opossum)a | nd | 0.710 | nd | nd | − | nd | 0.850 | nd | nd | iso | [53] | ||
| placentals | |||||||||||||
| Carnivora | |||||||||||||
| Canis latrans (coyote) | 13 | −1.183 | 1.720 | 1.601, 1.884 | 0.974 | + | nd | nd | nd | nd | [33] | ||
| Panthera tigris (tiger) | 13 | −0.517 | 1.360 | 1.283, 1.473 | 0.983 | + | 12 | −0.002 | 1.330 | 1.245, 1.440 | 0.986 | + | [33] |
| Ursus americanus (black bear) | 19 | 0.095 | 1.240 | 0.974, 1.347 | 0.966 | iso | 16 | 1.372 | 1.370 | 0.843, 1.161 | 0.939 | iso | [33] |
| Cetartiodactyla | |||||||||||||
| Connochaetes taurinus (blue wildebeest) | 15 | 1.714 | 0.800 | 0.738, 0.875 | 0.976 | − | 13 | 1.844 | 0.860 | 0.805, 0.924 | 0.988 | − | [33] |
| Bison bison (bison) | 16 | 1.785 | 0.790 | 0.707, 0.908 | 0.958 | − | 12 | 1.560 | 0.870 | 0.805, 0.995 | 0.971 | − | [33] |
| Proboscidea | |||||||||||||
| Loxodonta africana (African elephant) | 11 | 1.632 | 0.900 | 0.618, 1.038 | 0.946 | iso | 7 | 1.849 | 0.860 | 0.632, 0.946 | 0.984 | iso | [33] |
| femur | tibia | ||||||||||||
| taxon | n= | Y-int | slope | 95% CI limits | R2 | allometry | n= | Y-int | slope | 95% CI limits | R2 | allometry | ref |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| marsupials | |||||||||||||
| Thylacinus cynocephalus (Tasmanian tiger) | 13 | 0.660 | 1.241 | 1.179, 1.303 | 0.994 | + | 13 | 0.690 | 1.277 | 1.211, 1.344 | 0.994 | + | this study |
| Trichosurus Vulpecula (brushtail possum)a | 51 | nd | 0.922 | nd | 0.867 | + | 51 | nd | 0.876 | nd | 0.944 | − | [32] |
| Macropus eugenii (tammar wallaby)a | 25 | nd | 0.854 | nd | 0.965 | − | 22 | nd | 0.402 | nd | 0.716 | − | [32] |
| Monodelphis domestica (short-tailed opossum)a | nd | 0.890 | nd | nd | iso | nd | 0.890 | nd | nd | iso | [53] | ||
| placentals | |||||||||||||
| Carnivora | |||||||||||||
| Canis latrans (coyote) | 13 | −0.788 | 1.640 | 1.457, 2.087 | 0.949 | + | 9 | −1.883 | 1.98 | 0.567, 2.263 | 0.905 | iso | [33] |
| Panthera tigris (tiger) | 15 | −0.721 | 1.460 | 1.389, 1.581 | 0.985 | + | 12 | −0.736 | 1.45 | 1.319, 1.651 | 0.98 | + | [33] |
| Ursus americanus (black bear) | 19 | 0.266 | 1.270 | 0.965, 1.395 | 0.959 | iso | 16 | 1.091 | 1.04 | 0.863, 1.138 | 0.95 | iso | [33] |
| Cetartiodactyla | |||||||||||||
| Connochaetes taurinus (blue wildebeest) | 15 | 1.261 | 0.960 | 0.920, 1.017 | 0.989 | − | 15 | 1.851 | 0.88 | 0.8268, 0.9357 | 0.989 | − | [33] |
| Bison bison (bison) | 16 | 1.427 | 0.920 | 0.8634, 0.9969 | 0.975 | − | 17 | 2.232 | 0.75 | 0.6370, 0.8947 | 0.932 | iso | [33] |
| Proboscidea | |||||||||||||
| Loxodonta africana (African elephant) | 11 | 1.565 | 0.950 | 0.700, 1.069 | 0.972 | iso | 10 | 1.201 | 0.97 | 0.597, 1.096 | 0.94 | iso | [33] |
aRMA calculated with long bone midshaft width.