. New theropod and ornithischian dinosaur footprints at the Dinosaur Footprint State Reservation (Early Jurassic, Portland Formation), Holyoke, Massachusetts, USA LEPORE, Taormina, University of Massachusetts, Amherst, MA, USA

Table 1: Averages FW Pr III Table 2: Velocities Figure 2 Relative Genus FP FL (cm) (cm) AD (cm) R (cm) L/W R' (cm) P' (cm) stride DFSR Site Map Average 5.4-16 42-72 unavailable ~2.5-4.0 Average h length (Anomoepus prints Anomoepus 94 16.1 14.2 49 3.2 12.9 1.1 14.2 7.4 Ostrom's Trackways L (cm) Average L (m) Velocity (m/s) Average λ (λ/h) shown in red) Anomoepus 98 13.1 11.5 62 4.6 8.5 1.1 9.9 3.1 26 1 (31) 23.5 21.4 0.96 x x x 2 (43) 19.3 Figure 1 Average <15 10 to 30 ~2 ~1.3 24 1 (61) 33.1 29.73 1.46 2.26 2.46 1.68 Location near Grallator 289 16.4 12 41 6.4 10 1.4 10.7 1.9 Grallator 296 18.5 10 31 8 10.5 1.9 10.9 1.4 2 (76) 29.8 Mount Tom 3 (40) 29.8 (Ostrom, 1972) 4 (51) x 5 (58) 26.2 Average >25 24-40 ~1.4-1.5 ~2.2 25 Eubrontes 76 29.8 18.2 46 7.5 22.3 1.6 24.2 4.3 1 (392) 38 36.03 1.77 1.76 2.42 1.37 Eubrontes 61 33.1 19.6 42 8.5 24.6 1.7 26.4 3.9 2 (153) 35.1 Eubrontes 272 38.5 24 45 14 24.5 1.6 26.5 2.2 3 (393) 35 23 Average 15-25 20-35 ~2.0 >1.3<1.8 1 (251) 39 38.75 1.9 1.45 2.27 1.19 2 (263) x Anchisauripus 121 18 10.3 58 6.5 11.5 1.7 13.1 2.7 3 (272) 38.5 Anchisauripus 123 17.6 10.1 29 2.5 15.1 1.7 15.6 7.8 FP=Footprint Number, FL=Footprint Length, FW=Footprint Width, AD=Angle of divarication between digits II and IV, Pr Equations III=Projection of digit III, R=Rear projection, L/W=Length to width ratio, R’=Corrected rear projection of the foot, • P’=Corrected projection of digit III. Footprint Length (L) to Footprint Width (W) ratio: L / W (Olsen, et al., 1998) • Corrected rear projection (R′) of the foot: R′ = R * [1/cos(θ/2)] where θ is the angle of divarication between digits II and IV. (Olsen, et al., 1998) • Corrected projection (P’) of digit III: P′ = R′ / (T-R′) where R′ is the corrected rear projection of the foot and T is total footprint length. • Hip height of the Eubrontes trackmaker using two equations based on morphometric ratios that utilize total Figure 3 footprint length, where h is the animal’s height at the hip (Thulborn, 1989, 1990). Corresponding For a footprint length >25cm: h ≈ 4.9 * footprint length (FL) A Flurry of Activity Around Previously-Mapped Eubrontes Tracks eight meters of For a footprint length <25 cm: h ≈ 4.5 * footprint length (FL) Ostrom’s map • Trackmaker velocity: u ≈ 0.25g0.5 λ1.67 h-1.17 • The Dinosaur Footprint State Reservation (DFSR) site sits in the Hartford Basin in Holyoke, Massachusetts, near (Ostrom, 1972) where u is velocity, g is acceleration due to free fall, λ is stride length and h represents the trackmaker’s hip height the Northampton, Massachusetts town line (Figure 1). It has been recognized as bearing footprints since the (Alexander, 1976). • Stride to hip height ratio (relative stride length): λ/h = relative stride length 1830s, when Edward Hitchcock labeled the site “the quarry in Northampton, on the east side of Mount Tom” to determine whether the animals were walking, trotting or running, where λ is stride length in meters and h is hip (Hitchcock, 1836) and used the locality as the source for his type specimen of the ichnospecies Eubrontes height (Thulborn, 1982). giganteus (Amherst College (AC) 15/3; Olsen, et al., 1998). • The site is located in the lower Portland Formation directly above the Hampden Basalt, and is approximately 201 Acknowledgements

million years old, of Hettangian age. The strata are part of the Newark Supergroup, which parallels much of the Literature Cited I would like to warmly thank the following northeast North American Atlantic coast. Situated in the rift lake valleys of Hettangian New England, the shallow individuals for their invaluable assistance during this Alexander, R. McN. 1976. Estimates of speeds of project: Dr. Margery Coombs (UMass Amherst), Dr. lake associated with this deposit served as a water source for the local ecosystem, as is clear from the vast amount dinosaurs. Nature, 261: 129-130. Bruce Byers (UMass Amherst), Sebastian Dalman of bioturbation. (UMass Amherst), Patrick Getty (UMass Amherst), Getty, P. 2005. Ornithischian ichnites from Dinosaur Eric Dewar (Suffolk), Dr. Rebecca Mattison • Footprint Reservation (Early Jurassic Portland (Wellesley), Cynara Cannitella (Wellesley), Liza In summer 2005 I mapped 343 partial or complete dinosaur footprints within the southernmost quarter of the Formation), Holyoke, MA. Journal of Vertebrate Above: Anomoepus (scale 10 cm). Mattison, Jeff Bonzek, Bobbie Douglass, Amanda site, including the theropod ichnogenera Eubrontes, Anchisauripus and Grallator. Among the prints mapped were Paleontology (3, Supplement):63A. Detailed pad definition, relatively short Stone, David Freedman, Marlene, Andrew and eight previously unidentified prints of the ichnogenus Anomoepus, representing a basal ornithischian trackmaker. projection of digit III, metatarsal Katrina Lepore. Hitchcock, E.H. 1836. Ornithichnology.—Description Above: Eubrontes (scale 5 cm). impression in line with axis of digit III. The new map (Figure 2) demonstrates the abundance of animal activity. Footprint measurements were taken to of the footmarks of birds, (Ornithichnites) on New Red Note relatively long projection of digit III. Sandstone in Massachusetts. American Journal of aid in identification, and corroborated with average measurements described by Lull (1953) (Table 1). Science 29(ser. 1):307-340. • 16 Eubrontes prints corresponding to four trackways were mapped. The trackways were measured to determine Lull, R.S. 1953. Triassic life of the Connecticut valley. Conclusions trackmaker velocity and whether the trackmaker was walking, trotting or running (Table 2). State of Connecticut, State Geological and Natural History Survey Bulletin 81:1-336. • 38 square meters mapped, 1/4 of total site area •The site and the rocks adjacent to it have been analyzed by several other workers. In 1972 the site was mapped Olsen, P.E., Smith, J.B., and McDonald, N.G. 1998. • Cyclical lacustrine environment partially by Dr. John Ostrom of Yale University, who noted the directionality of nearly all the Eubrontes trackways Type material of the type species of the classic • 343 partial or complete bipedal dinosaur footprints and argued the likelihood of gregarious social behavior in theropod dinosaurs (Ostrom, 1972). theropod footprint genera Eubrontes, Anchisauripus, and Grallator (Early Jurassic, Hartford and Deerfield • Individual prints with no apparent preferred orientation, excluding Eubrontes tracks Tracks of Eubrontes are by far the most noticeable and largest at the site, and form the only definite footprint Basins, Connecticut and Massachusetts, U.S.A.). Journal of Vertebrate Paleontology, 18(3):586-601. • Tracks that could be accurately identified to the genus level include the theropod ichnogenera Eubrontes, trackways discernable within the first eight meters, in accordance with Ostrom’s map (Figure 3). Ostrom mapped Anchisauripus and Grallator. Eight of the prints are Anomoepus, representing a basal ornithischian. Ostrom, J.H. 1972. Were some dinosaurs 18 Eubrontes tracks within these eight meters; four on Ostrom’s original map could not be found, and two new gregarious? Palaeogeography, Palaeoclimatology, • A new map (Figure 1) demonstrates the abundance of identifiable footprints previously overlooked due to Eubrontes tracks were identified. Although Ostrom’s survey focused on the Eubrontes prints, his map also Palaeoecology, 11:287-301. poor preservation included four Anchisauripus trackways or individual footprints, as well as two Grallator trackways—two additional Thulborn, R.A. 1982. Speeds and Gaits of Dinosaurs. • The new map shows the spatial relationship between Eubrontes and non-Eubrontes tracks theropod ichnogenera. Palaeogeography, Palaeoclimatology, Palaeoecology, 38:227-256. • 16 Eubrontes tracks corresponding to four trackways, velocities ranging from 1.45 to 2.26 meters per • Olsen et al. (1998) have also studied the footprints in the rocks exposed closer to the river. second (5.22 to 8.14 kilometers per hour), indicating walking trackmakers Thulborn, R.A. 1989. The Gaits of Dinosaurs. In • Getty (2004) noted the presence of several Anomoepus trackways and individual footprints, including one Gillette, D.D., and Lockley, M.G. (eds.), Dinosaur • Demonstrates the ecological diversity represented at this site Tracks and Traces, Cambridge University Press, New • noticeable trackway with a possible tail-drag mark. His observations and the several Anomoepus individual York, pp. 39-50. Site is badly weathered due to visitor traffic, exposure, weathering of undertracks •Further exploration of this site will undoubtedly uncover a great deal more of the ecological and behavioral footprints I observed are clear indication that theropod footprints are not the only footprints located at the DFSR, Thulborn, R.A. 1990. Dinosaur Tracks. Chapman contrary to what Ostrom (1972) had previously assumed. and Hall, London, 410 pp. picture of dinosaurian taxa in the Early Jurassic strata of Massachusetts