Figure 1.
A comparison of crania in juvenile and adult Smilodon spp. scaled to the same condylobasal length.
A, juvenile S. populator (NRM); B, adult S. populator (BM, cast); C, juvenile S. fatalis (PC coll.; from Dinocasts); D, adult S. fatalis (LACMHC2001-173). Scale bars equal 5 cm.
Figure 2.
A comparison of mandibles in juvenile and adult Smilodon spp. scaled to the same overall length.
A, juvenile S. populator (NRM); B, adult S. populator (CN52); C, juvenile S. fatalis (PC coll.; from Dinocasts); D, adult S. fatalis (LACMHC3E-350). The juvenile S. fatalis mandible is an example of a gracile mandible type whereas the adult mandible is of a more robust type, but variation in juveniles and adults in the La Brea material is substantial. Scale bars equal 5 cm.
Figure 3.
A comparison of crania in juvenile and adult extant felids scaled to the same condylobasal length.
A, Neofelis diardi juvenile (RMNH3518); B, Neofelis diardi adult (RMNH 71/41); C, Panthera onca juvenile (RMNH3212); D, Panthera onca adult (CN842); E, Panthera tigris juvenile (CN5654); F, Panthera tigris adult (RMNH “n”). Scale bars equal 5 cm.
Figure 4.
A comparison of mandibles in juvenile and adult extant felids scaled to the same overall length.
A, Neofelis diardi juvenile (RMNH3518); B, Neofelis diardi adult (RMNH “a”); C, Panthera onca juvenile (RMNH3212); D, Panthera onca adult (CN842); E, Panthera tigris juvenile (CN1523); F, Panthera tigris adult (CN772). Scale bars equal 5 cm.
Figure 5.
Illustration of a skull of Smilodon fatalis (LACMHC2001–3) showing landmarks used in the analysis.
Landmarks on the cranium are: 1, top of cranium at the junction of sagittal and nuchal crests; 2, top of occipital condyle; 3, dorsal extent of the mastoid musculature; 4, apex of paroccipital process; 5, apex of mastoid process; 6, centre of external auditory meatus; 7, posterior base of zygomatic arch; 8, ventral junction of jugal-squamosal suture; 9, centre of mandibular condyle; 10, base of postorbital process (jugal portion); 11, apex of postorbital process (frontal portion); 12, centre of orbital aperture; 13, junction of jugal-maxilla suture; 14, posterior, and 15, anterior edge of P4 (dP4 in juveniles); 15, posterior, and 16, anterior edge of P3 (dP3 in juveniles); 17, posterior, and 18, anterior edge of C1 (dC1 in juveniles); 19, anterior edge of premaxilla at incisor alveolus; 20, ventral edge of external narial aperture; 21, apex of nasal; 22, dorsal, and 23, ventral edge of infraorbital foramen; 24, dorsal edge of maxilla-frontal suture; 25, dorsal edge of centre of frontal postorbital process; 26, dorsal edge of beginning of temporal fossa. Landmarks on the mandible are: 1, apex of mandibular cotyle; 2, posterior, and 3, anterior base of coronoid process; 4, apex of coronoid process; 5, posterior, and 6, anterior edge of retroarticular process; 7, anterior extent of mandibular (M. temporalis) adductor musculature; 8, posterior, and 10, anterior edge of M1 (in the included juveniles, M1 is un-erupted but the alveolar orifice and scar can easily be made out); 10, posterior, and 12, anterior edge of P4 (dP4 in juveniles); 14, posterior, and 15, anterior edge of C1 (dC1 in juveniles) at the alveolar border; 16, ventral edge of mandibular symphysis; and the depth of the horizontal mandibular ramus posterior to M1 (8, 9), at the M1/P4 junction (10, 11); and anterior to P4 (12, 13). Scale bar equals 5 cm.
Figure 6.
Comparison of cartesian deformation grids illustrating ontogenetic net shape changes in crania of Smilodon spp. and extant pantherines.
A, Smilodon fatalis; B, S. populator; C, Neofelis diardi; D, Panthera onca; and D, P. tigris.
Figure 7.
Comparison of cartesian deformation grids illustrating ontogenetic net shape changes in mandibles of Smilodon spp. and extant pantherines.
A, Smilodon fatalis; B, S. populator; C, Neofelis diardi; D, Panthera onca; and D, P. tigris.