Content uploaded by Patrick Ryan Getty
Author content
All content in this area was uploaded by Patrick Ryan Getty on Apr 29, 2015
Content may be subject to copyright.
Was the Eubrontes Track Maker Gregarious?
Testing the Herding Hypothesis at Powder Hill Dinosaur Park,
Middlefield, Connecticut
Patrick R. Getty1, Laurel Hardy2and Andrew M. Bush3
1 Corresponding author: Center for Integrative Geosciences, University of Connecticut,
354 Mansfield Road, U-1045, Storrs, CT 06269 USA
—email: patrick.getty@uconn.edu
2 1476 Poquonock Avenue, Windsor, CT 06095 USA
—email: leraducha@gmail.com
3 Department of Ecology and Evolutionary Biology, University of Connecticut,
75 North Eagleville Road, U-3043, Storrs, CT 06269 USA
—email: andrew.bush@uconn.edu
ABSTRACT
The theropod footprint taxon Eubrontes is common in Early Jurassic rocks of the Hartford Basin.
Aligned Eubrontes trackways at one site in Holyoke, Massachusetts, have led to the hypothesis
that the track makers were gregarious; however, trackways are not aligned at several other sites.
To test the gregariousness hypothesis, we measured trackway orientations at Powder Hill Di-
nosaur Park in Middlefield, Connecticut, where exposed rocks were deposited in an ephemeral
lake environment, and compared these orientations to those of two additional track sites from
similar sedimentary facies. The Eubrontes trackways produced in the ephemeral lake environ-
ments have no preferred orientation and provide no evidence of gregarious behavior. We suggest
that the alignment of tracks in Holyoke reflects behavior in response to environmental settings
rather than group behavior. Trackways may be aligned next to large, permanent lakes because of
shoreline-parallel travel, but random orientations characterize other habitats. This study under-
scores the value of examining track sites from different paleoenvironments when inferring di-
nosaur behavior.
KEYWORDS
Gregariousness, ichnology, trackway, theropod, Jurassic, Hartford Basin, Newark Supergroup
Bulletin of the Peabody Museum of Natural History 56(1):95–106, April 2015.
© 2015 Peabody Museum of Natural History, Yale University. All rights reserved. • http://peabody.yale.edu
Introduction
Dinosaur tracks and trackways are sedimentary
structures produced by living animals interacting
with the environment. As such, they offer unique
insights into the behavior of their makers that may
be unavailable from skeletal material. One of the
many behaviors that can be evaluated from tracks
and trackways is group behavior, or gregarious-
ness. Among the first to propose group behavior
for dinosaurs was Edward Hitchcock, who in 1836
argued that the parallel alignment of Eubrontes
trackways in Holyoke, Massachusetts, was evi-
dence of gregariousness. Today these tracks are
ascribed to theropod dinosaurs, but Hitchcock
(1836) attributed them to large birds (dinosaurs
were named several years later by Owen [1842]).
More than a century later, John Ostrom of Yale Uni-
versity visited the Holyoke site and described his
findings in a seminal paper on dinosaur gregari-
ousness (Ostrom 1972). Although he argued that a
herd produced the parallel trackways, Ostrom also
noted that parallelism could result from animals
walking along geographic features such as shore-
lines, which formed physical barriers. Ostrom pro-
posed that herding could be differentiated from
obstacle avoidance if the tracks of other animals
were oriented obliquely to the proposed herd,
because a physical barrier presumably should affect
the direction of travel for all animals.
Since he publication of Ostrom’s paper vari-
ous authors have proposed additional lines of evi-
dence that can be used to support the hypothesis
that a particular suite of trackways was produced
by a herd. For example, Currie (1983) observed
10 hadrosaur trackways that, in addition to being
parallel, took the same turn. Lockley et al. (1986)
pointed to the consistent spacing between sauro-
pod trackways as evidence for group behavior.
Cotton et al. (1998) argued that velocity calcula-
tions derived from supposedly herding animals
should yield similar speeds. Thulborn (1990) and
Lockley (1991) have summarized even more lines
of evidence to support gregariousness, such as
similar depths among trackways that were pre-
sumably made at the same time.
In this paper we describe a suite of dinosaur
tracks from ephemeral lake deposits of the Early
Jurassic East Berlin Formation of Middlefield,
Connecticut, USA. We measured the orientations
of these tracks to test for alignment. We compare
these results to those from other track sites in
ephemeral lake deposits of the Hartford Basin, as
well as those from the perennial lake deposits of
Holyoke, Massachusetts, where Hitchcock (1836)
and Ostrom (1972) observed parallel trackways.
We propose that evaluating trackway parallelism
across different paleoenvironments can test
claims of gregarious behavior.
Historical Context
In the 19th century the Coe family of Middlefield
owned the land that would become Powder Hill
Dinosaur Park. Between 1848 and 1849, stone
from a small quarry on the property was used to
construct a dam and form Beseck Lake, which
provided power to local factories (Atkins 1883:26).
Dinosaur tracks were discovered during the quar-
rying process (Warner and Fowler 1966; Austin
1976), and A.M. Bailey, the engineer who
designed the dam, had slabs with the best tracks
placed on top so that they were visible to those
crossing the dam (Thompson 1996).
Wesley R. Coe (b. 1869), who later became
Curator of Zoology at Yale’s Peabody Museum of
Natural History, donated the quarry to the Univer-
sity in 1929 (“Town acquires...” 1976). For nearly
50 years Yale maintained the locality as a public
educational site, complete with explanatory signs
(Barclay 1941; “Week-long activities...” 1966). In
1976, however, Yale turned ownership over to the
town of Middlefield (“Town acquires...”1976),
which has since managed the site as a municipal
park. Tracks at the site have been vandalized at least
once (Austin 1976), but a significant number
remain and these are the subject of the present
study.
Geological Context
Powder Hill Dinosaur Park is located at lat
41°30⬘11.48⬙N, long 72°43⬘48.73⬙W (Figure
1A–C). The exposure at the park consists of
approximately 2.3 m of mudstone and fine- to
coarse-grained sandstone from the East Berlin
Formation of the Hartford Basin, which is part of
the Mesozoic Newark Supergroup of eastern
North America (Figure 1C–D). The basin, which
filled with approximately 5 km of sediment and
basaltic lava flows (Wenk 1984), is a half graben
that formed during the breakup of Pangea during
the Late Triassic and Early Jurassic (Olsen 1997).
The East Berlin Formation ranges from 145 to 450
m thick (Hubert et al. 1976) and consists of cycli-
cally repeating units of red mudstones and gray to
black shales of Early Jurassic age (Cornet et al.
1973). The red mudstones formed in playa envi-
ronments, whereas the darker shales formed in
perennial oligomictic alkaline lakes. The alterna-
tion from playa to permanent lake deposition
resulted from climactic changes driven by
Milankovich Cycles (Olsen 1986). At their great-
est extent, the lakes that filled the basin during
deposition of the East Berlin Formation are esti-
mated to have been tens of meters deep and to
have extended over 4,700 km2(Hubert et al. 1976;
Hubert et al. 1992).
The strata at Powder Hill Dinosaur Park
strike 12° and dip 20° to the east. Dinosaur tracks
are preserved on four separate beds on the quarry
floor (referred to as Beds One through Four, with
Bed One stratigraphically lowest). Bed One forms
the quarry floor. Beds Two, Three and Four are
23 cm, 38 cm and 45 cm above Bed One, respec-
tively. All of these beds are composed of muddy,
fine-grained sandstone that preserve oscillation
ripple marks and desiccation cracks, indicating
deposition at the edge of a shallow lake that sub-
sequently experienced significant drying. Other
beds seen in cross section within the quarry walls
also have ripples and mudcracks, and several beds
consist of coarse-grained, cross-bedded sands that
form small channels, indicating a fluvial influence
Bulletin of the Peabody Museum of Natural History 56(1) • April 2015
96
Was the Eubrontes Track Maker Gregarious? • Getty et al. 97
in the shallow lacustrine deposits. Additional sed-
imentary structures preserved in cross section
include soft-sediment deformation features.
Invertebrate bioturbation is limited to a few hori-
zontal burrows.
Methods
The dinosaur tracks were identified under low-
angle light conditions in the early morning and
late afternoon. We recorded the length, width,
Figure 1. Geological and geographical context of Powder Hill Dinosaur Park. A, Oblique view looking west
into the quarry, showing the multiple beds preserved there. Scale bar (just above center right) is 1 m. B, Distri-
bution of Mesozoic-aged sedimentary and igneous rocks (gray) in Connecticut. C, Enlarged view of the boxed
area in B, showing the bedrock geology of Middlefield, Connecticut, in the vicinity of the park. Modified from
Rodgers (1985). D, Partial geological column of the Hartford basin illustrating the approximate stratigraphic
position of the park within the East Berlin Formation. Abbrev iations: Jeb, Jurassic East Berlin Formation; Jha,
Jurassic Hampden Basalt; Jho, Jurassic Holyoke Basalt; Jp, Jurassic Portland Formation; Jr, Jurassic; Jsm, Juras-
sic Shuttle Meadow Formation; Jta, Jurassic Talcott Basalt; Tr, Triassic; Trnh, Triassic New Haven Arkose.
angle of divarication and digit III projection for
each track, where possible (Olsen et al. 1998:588,
fig. 3). The tracks were assigned to ichnogenera
with reference to these dimensions according to
revised diagnoses for Eubrontes, Anchisauripus,
Grallator and Anomoepus provided by Olsen et al.
(1998) and Olsen and Rainforth (2003). Olsen
(1980) and Rainforth (2005) argued that the
theropod ichnogenera Anchisauripus and Gralla-
tor can be synonymized with Eubrontes, but we
use all three names here because they conve-
niently convey useful information on track size
and morphology.
The site was mapped by hand by constructing
a 1 m2grid directly on the quarry floor using
chalk. The boundaries of the individual beds and
the positions of the dinosaur tracks were recorded
on graph paper to create a preliminary map that
was later digitized. The number of individuals
leaving tracks was estimated by assuming that a
single animal made one trackway or isolated track,
and did not re-cross the surface. This approach
was somewhat difficult for Bed Two, which is
exposed discontinuously in different parts of the
quarry. We attempted to link trackway segments
on different parts of Bed Two according to simi-
larities in size, shape, orientation and preserva-
tion. It is possible, however, that some trackways
were counted twice when preserved on different
exposures of the bed.
The orientations of sedimentary structures
and tracks were measured using a Brunton com-
pass. Oscillation ripple crest orientations were
recorded to estimate the direction of the pale-
oshoreline, since such ripple marks form parallel
or oblique to modern shores (Nichols 1999:54).
Most dinosaur trackways were relatively straight
and their orientations were measured from the
bearing of a string run through their midlines. The
direction of locomotion for dinosaurs that left iso-
lated tracks was estimated from the compass bear-
ing of the track, as measured along the length of
digit III. The PAST software package (Hammer
2013) was used to plot orientations and evaluate
the statistical significance of directional trends.
Results
Number and Types of Tracks
One hundred twenty-four dinosaur tracks
were identified on the four beds at Powder Hill
Dinosaur Park (Figures 2 and 3). All of the tracks,
except for four that are too poorly preserved to
assign to a taxon, are attributed to the ichnogen-
era Grallator, Anchisauripus and Eubrontes,
which were made by small-, medium- and large-
sized theropods, respectively (Olsen et al. 1998;
Smith and Farlow 2003). Although McHone
(2004:127) indicated that the ornithischian track
Anomoepus was present at the site, we were
unable to find any tracks of this type.
Bed One, the largest in areal extent, preserves
only 12 tracks made by five individuals, including
four large theropods that left Eubrontes tracks and
trackways, and a single smaller theropod that left
an Anchisauripus trackway. The tracks were made
when the sediment was wet and soupy, as evi-
denced by push-up rims surrounding both large
and small tracks. Consequently, the tracks lack
fine details of the foot morphology.
Bed Two, which was separated into six sec-
tions by quarrying, preserves 81 tracks attributa-
ble to Grallator, Anchisauripus and Eubrontes.
Detail within the tracks is variable. Some Eubrontes
are deep and could represent true tracks, although
some of these are filled with overlying rock (see
Figure 2A–B), making them difficult for many
visitors to see. Other Eubrontes have deeply
impressed toe tips with claw imprints, but faintly
preserved proximal imprints, suggesting that
they are shallow undertracks (see Figure 2C–D).
Yet other Eubrontes are shallow and have faint
outlines that grade into the surrounding bed,
even at the tips of the toes, suggesting that they
are deep undertracks (see Figure 2E–F). The
smaller Grallator preserved on Bed Two are
among the best-preserved tracks at the site. They
show toe pad and claw imprints and are likely
true tracks or very shallow undertracks (see Fig-
ure 2K–N). We estimate that Bed Two reflects the
activities of 30 Eubrontes track makers, 10
Anchisauripus track makers and six Grallator
track makers. We were unable to identify the
tracks of four individuals because they are too
poorly preserved.
Beds Three and Four preserve only Eubrontes
tracks. Four animals on Bed Three made 6 tracks,
whereas 12 animals left 25 tracks on Bed Four. As
with the tracks on Beds One and Two, the
Eubrontes on Beds Three and Four are variable in
their preservation and range from relatively deep
tracks with well-developed boundaries to shallow
Bulletin of the Peabody Museum of Natural History 56(1) • April 2015
98
tracks with faint boundaries. As such, the tracks
probably represent a combination of true tracks
and undertracks.
Ripple and Track Orientations
The orientations of the crests of 89 oscillation rip-
ples were measured on Beds One to Three (55
from Bed One, 5 from Bed Two and 29 from Bed
Three). The average ripple orientation varies lit-
tle among beds and shows a strong north-north-
east to south-southwest trend, suggesting a
north-south or northeast-southwest trending
shoreline (Figure 4A).
When the trackways and isolated tracks from
all four beds are considered together, they show a
fairly uniform distribution (Figure 4B). Consid-
ered independently, the beds still lack a preferred
orientation. Beds One and Three, for example,
preserve the prints of four Eubrontes track makers
each, but none of these parallel each other (see
Figure 3). The Eubrontes trackways on Bed Four
have a stronger mode in the northeast (Figure
4C), but it is not statistically significant. Further-
more, one of the tracks (69.1 in Figure 3) is sig-
nificantly shallower than the others and is likely
an undertrack, indicating that it was made at a
later time than the other three trackways with a
similar orientation. Bed Two, which preserves the
largest number of trackways, shows no preference
in orientation for Eubrontes tracks (Figure 4D) or
for those made by smaller theropods (Figure 4E).
Discussion
Although some researchers (e.g., Coombs 1990;
Roach and Brinkman 2007) have argued that par-
allelism in the Eubrontes trackways at Dinosaur
Footprint Reservation in Holyoke, Massachusetts,
likely resulted from the presence of a physical bar-
rier, most researchers have taken the evidence to
mean that the track maker was gregarious (Hitch-
cock 1836, 1848, 1858; Bain and Meyerhoff 1963;
Ostrom 1972). Indeed, this is a classic locality that
is often discussed in summaries of dinosaur social
behavior (e.g., Thulborn 1990; Lockley 1991; Lock-
ley and Matsukawa 1999; Meyers and Fiorillo 2009;
Was the Eubrontes Track Maker Gregarious? • Getty et al. 99
Figure 2. Representative dinosaur tracks from Powder Hill Dinosaur Park, with interpretive line drawings. A,
B, Right Eubrontes track with matrix infill. C, D, Eubrontes undertrack exhibiting shallow proximal and deep dis-
tal portions of the foot. E, F, Deep Eubrontes undertrack with faint outlines. G, H, Right Eubrontes track. I, J, Left
Anchisauripus track. K, L, Right Grallator track. Mand N, Left Grallator track showing slip marks behind the
track.
Bulletin of the Peabody Museum of Natural History 56(1) • April 2015
100
Figure 3. Map of the quarry floor showing the distribution of dinosaur tracks on the four exposed beds. Because
of the poor preservation of most tracks, they are represented by stylized symbols to assist with ichnotaxonomic
identification.
Currie and Eberth 2010; García-Ortiz and Pérez-
Lorente 2014). Thus, there is no consensus of opin-
ion about the parallel trackways at Dinosaur
Footprint Reservation. We argue that the gregari-
ousness hypothesis can be further evaluated by
examining other track sites in the Hartford Basin,
since these should also show parallelism if the ani-
mal regularly traveled in herds.
In contrast to this prediction, however, the
trackways on the four beds at Powder Hill
Dinosaur Park are randomly oriented, and are
thus similar to those at Dinosaur State Park in
Rocky Hill, Connecticut (Ostrom 1972; Farlow
and Galton 2003), and the Murray Quarry in
Holyoke, Massachusetts (Getty 2005), where
trackway parallelism has not been observed. In
addition, the tracks on Beds Two, Three and Four
at Powder Hill were made over time, as is evi-
denced by the co-occurrence of true tracks and
undertracks. Getty (2005) observed true tracks
and undertracks at the Murray Quarry as well.
Consequently, the evidence from these sites,
which are all from playa lake depositional facies,
does not support the idea that the track maker
was gregarious. Rather, it suggests that the
Eubrontes track maker was solitary and that the
Was the Eubrontes Track Maker Gregarious? • Getty et al. 101
Figure 4. Rose diagrams of oscillation ripple marks and dinosaur tracks at Powder Hill Dinosaur Park. A, Oscil-
lation ripple orientations show a northwest to southeast trend, which we infer to reflect the direction of the pale-
oshoreline. B, Composite rose diagram of all trackways and isolated tracks on all four beds, showing the random
distribution of trackways that accumulated with time. C, Rose diagram of trackways on Bed Four. Although
there is a stronger trend to the northeast, it is not statistically significant. Furthermore, the preservation of some
trackways as undertracks indicates that not all animals trended in that direction at the same time and thus were
unlikely to be moving as a group. D, Rose diagram of all Eubrontes trackways and isolated tracks on Bed Two,
showing a random distribution. E, Rose diagram of all small theropod (Grallator and Anchisauripus) trackways
and isolated tracks on Bed Two. Note that the scale for the ripples is different than that for the rose diagram illus-
trating track orientations.
parallelism observed at Dinosaur Footprint Reser-
vation is unique to that site.
If the Eubrontes track maker was not gregar-
ious, then something else must have caused the
parallelism seen at Dinosaur Footprint Reserva-
tion. Getty et al. (2012) conducted an in-depth
remapping of this site and showed that the
Eubrontes orientations are strongly bimodal and
nearly coincident with the orientations of the
crests of oscillation ripples found below and
above the main track bed. This additional data
collected by Getty et al. (2012) supports the
hypothesis that the animals were following a
shoreline, as had previously been argued by
Coombs (1990) and Roach and Brinkman
(2007). Desiccation cracks are absent on the main
track-bearing bed at Dinosaur Footprint Reser-
vation, indicating that the lake was relatively sta-
ble, such that it could have influenced the
direction of travel of many individual animals
over time. More evidence supporting the idea
that the shoreline influenced the animals’ direc-
tions of travel comes from trackways on beds 69
m above those on the main bed, which show
nearly the same preferred orientation (Smith and
Smith 1996; Getty et al. 2012). Considering that
evidence for shoreline-paralleling behavior has
been observed or inferred at other dinosaur track
sites throughout the Mesozoic (Thorpe 1929;
Godoy and Leonardi 1985; Lockley et al. 1986;
Lockley 1991; Irby 1996; Weems 2006; Schu-
macher and Lockley 2014), it is not surprising
that some Hartford Basin dinosaurs paralleled
the shores of the lakes that filled the rift valley.
Conclusions
The four track-bearing beds at Powder Hill
Dinosaur Park were deposited under shallow,
ephemeral lacustrine conditions. One hundred
twenty-three dinosaur tracks belonging to the
ichnogenera Eubrontes, Anchisauripus and Gralla-
tor are preserved at the site. As with other track
sites within the playa lake facies of the East Berlin
Formation, there is no preferred orientation to the
Eubrontes tracks at Powder Hill. This, along with
sedimentological data from Dinosaur Footprint
Reservation in the overlying Portland Formation
of Holyoke, Massachusetts, suggests that the pre-
ferred orientation of Eubrontes trackways at that
site resulted from shoreline-paralleling behavior.
Acknowledgments
We are indebted to Dan Brinkman and Barbara
Narendra of the Yale Peabody Museu m of Natural
History for providing information on the history
of Powder Hill Dinosaur Park. We are also
indebted to Benjamin Hamilton, who assisted in
cleaning up the site as part of his Eagle Scout proj-
ect. We kindly thank Daniel Vellone for providing
key references. We appreciate the efforts of Eben
Rose, who visited the site and discussed its sedi-
mentology with us. The published version of this
paper benefited tremendously from reviews pro-
vided by Spencer G. Lucas and Brian T. Roach.
Received 13 November 2014; revised and accepted
18 January 2015.
Bulletin of the Peabody Museum of Natural History 56(1) • April 2015
102
Appendix
Bed no. Track(way) no. Print no. Symmetry Length Ichnogenus Orientation
1 1 1.1 Right 21 Anchisauripus 336
1.2 Left 18
1.3 Right 19
1.4 Left 17
1.5 Right 17
22.1Left35Eubrontes 339
33.1 ? 33Eubrontes 268
44.1Left30Eubrontes 233
4.2 Right 32
4.3 Left 29
Continued
Was the Eubrontes Track Maker Gregarious? • Getty et al. 103
Continued
55.1Right40Eubrontes 5
5.2 Left 33
2A 6 6.1 ? ? Eubrontes 156
7 7.1 Right 37.5 Eubrontes 7
88.1Left39Eubrontes 268
8.2 Right 38
8.3 Left 42
99.1 ? ?Eubrontes 188
10 10.1 Left 37 Eubrontes 271
10.2 Right 34
10.3 Left ?
10.4 Right ?
11 11.1 Right 26 Eubrontes 322
11.2 Left 31
11.3 Right 28
11.4 Left ?
12 12.1 Left 25 Anchisauripus 92
12.2 Left 24
13 13.1 Left ? Eubrontes 115
13.2 Right 26
14 14.1 Left 29 Eubrontes 351
14.2 Right 29
2B 15 15.1 Left 38 Eubrontes 285
15.2 Right 37
16 16.1 ? 27 Eubrontes 155
17 17.1 Right 31 Eubrontes 171
18 18.1 ? ? Eubrontes Unclear
18.2 Left 33 207
19 19.1 ? ? Eubrontes Unclear
20 20.1 Left 35 Eubrontes 78
20.2 Left 29 Eubrontes
21 21.1 ? 49 Eubrontes 216
22 22.1 Right 37 Eubrontes 113
23 23.1 Left 16 Indeterminate 174
23.2
24 24.1 ? ? Eubrontes
2C 25 25.1 Left 20 Anchisauripus 169
26 26.1 Right 30 Eubrontes 67
26.2 Left
26.3 Right 28
27 27.1 Right 14 Grallator 113
27.2 Left 14
28 28.1 ? 15 Anchisauripus 115
29 29.1 ? ? Indeterminate 241
30 30.1 Right ? Indeterminate 262
31 31.1 Left 13 Grallator 206
32 32.1 Left 24 Anchisauripus 211
33 33.1 Left 26 Eubrontes 274
APPENDIX continued.
Bed no. Track(way) no. Print no. Symmetry Length Ichnogenus Orientation
Bulletin of the Peabody Museum of Natural History 56(1) • April 2015
104
33.2 Right ?
33.3 Left ?
34 34.1 Right 37 Eubrontes 87
34.2 Left ?
34.3 Right ?
34.4
35 35.1 Left 15 Anchisauripus 155
35.2 Right 15
35.3 Left ?
35.4 Right 16
36 36.1 Left 15 Grallator 281
37 37.1 ? ? Eubrontes 273
38 38.1 Left 28 Eubrontes 80
38.2 Left 33 Eubrontes
39 39.1 Left 40 Eubrontes 313
39.2 Left 37
39.3 Right 34
40 40.1 Left 13.5 Grallator 306
40.2 Right 13
41 41.1 ? 14 Grallator 226
2D 42 42.1 Left 17 Anchisauripus 34
43 43.1 Left 18 Anchisauripus 215
44 44.1 Left 40 Eubrontes 320
45 45.1 Left 30 Eubrontes 234
46 46.1 ? 14 Indeterminate 248
2E 47 47.1 Right ~36 Eubrontes 75
48 48.1 Left 16 Anchisauripus 341
49 49.1 Right 16 Anchisauripus 293
50 50.1 ? 14.5 Grallator 195
51 51.1 Right ? Eubrontes 175
52 52.1 ? ? Indeterminate 153
53 53.1 Right 37 Eubrontes 244
54 54.1 Left ? Anchisauripus 110
54.2 Left 16
3 55 55.1 Right 33 Eubrontes 325
56 56.1 Right 36 Eubrontes 10
57 57.1 Left ? Eubrontes 182
57.2 Right 39
58 58.1 Left 38 Eubrontes 359
58.2 Right 28
4 59 59.1 Left ? Eubrontes 94
59.2 Right 39
59.3 Left 39
59.4 Right 36
60 60.1 Right ? Eubrontes 280
60.2 Left 29
60.3 Right 27
61 61.1 Right ? Eubrontes 211
61.2 Left ?
APPENDIX continued.
Bed no. Track(way) no. Print no. Symmetry Length Ichnogenus Orientation
Continued
62 62.1 Left ? Eubrontes 35
62.2 Right ?
63 63.1 Right 33 Eubrontes 308
63.2 Left ?
63.3 Right 31
63.4 ? ?
64 64.1 ? 33 Eubrontes 33
65 65.1 Right ? Eubrontes 197
65.2 Left 34.5
66 66.1 Left 34 Eubrontes 45
66.2 Right 33.5
67 67.1 Right ? Eubrontes 35
67.2 Left 30
68 68.1 Left 36 Eubrontes 316
69 69.1 ? ? Eubrontes 11
70 70.1 Left ? Eubrontes 185
Was the Eubrontes Track Maker Gregarious? • Getty et al. 105
APPENDIX continued.
Bed no. Track(way) no. Print no. Symmetry Length Ichnogenus Orientation
Literature Cited
ATKINS, T. 1883. History of Middlefield and Longhill. Hartford:
Case, Lockwood, and Brainerd. 175 pp.
AUSTIN, D. 1976 July 10. Dinosaur tracks taken, stolen. The
Hartford Courant; p. 1 (1 p.). Available from: The Hartford
Courant Archives (1764–1986); http://pqasb.pqarchiver.
com/courant/advancedsearch.html
BAIN, G.W. AND H.A. MEYERHOFF. 1963. The Flow of Time in
the Connecticut Valley: Geological Imprints. Springfield:
Springfield Library and Museums Association. 129 pp.
BARCLAY, E.E. 1941 July 20. Outdoors. The Hartford Courant; p.
D2 (1 p.). Available from: The Hartford Courant Archives
(1764–1986); http://pqasb.pqarchiver.com/courant/advan
cedsearch.html
COOMBS, JR., W.P.1990. Behaviour patterns in dinosaurs. In:
D.B. Weishampel, P. Dodson and H. Osmólska, eds. The
Dinosauria. Berkeley: University of California Press. pp. 32–42.
CORNET, B., A. TRAVERSE AND N.G. MCDONALD. 1973. Fossil
spores, pollen, and fishes from Connecticut indicate Early
Jurassic age for part of the Newark Group. Science
182(4118):1243–1247.
COTTON, W.D, J.E. COTTON AND A.P. HUNT. 1998. Evidence
for social behavior in ornithopod dinosaurs from the Dakota
Group of Northeastern New Mexico, U.S.A. Ichnos
6(3):141–149.
CURRIE, P.J. 1983. Hadrosaur trackways from the lower Creta-
ceous of Canada. Acta Palaeotologica Polonica 28(1–2):
63–73.
CURRIE, P.J. AND D.A. EBERTH. 2010. On gregarious behavior
in Albertosaurus. Canadian Journal of Earth Science
47(1):1277–1289.
FARLOW, J.O. AND P. M. GALTON. 2003. Dinosaur trackways at
Dinosaur State Park, Rocky Hill, Connecticut. In: P.M.
LeTourneau and P.E. Olsen, eds. The Great Rift Valleys of
Pangea in Eastern North America. Volume 2, Sedimentol-
ogy, Stratigraphy, Paleontology. New York: Columbia Uni-
versity Press. pp. 248–262.
GARCÍA-ORTIZ, E. AND F. P ÉREZ-LORENTE. 2014. Palaeoecolog-
ical inferences about dinosaur gregarious behaviour based
on the study of tracksites from La Rioja area in the Cameros
Basin (Lower Cretaceous, Spain). Journal of Iberian Geology
40(1):113–127.
GETTY, P.R. 2005. Excavated and in situ dinosaur footprints
from the Murray Quarry (Early Jurassic, East Berlin For-
mation), Holyoke, Massachusetts, USA. Ichnos 12:
163–178.
GETTY, P.R., A. JUDGE, J. CSONKA AND A.M. BUSH. 2012. Were
early Jurassic dinosaurs gregarious? Reexamining the evi-
dence from Dinosaur Footprint Reservation in Holyoke,
Massachusetts. In: M. Thomas, ed. Guidebook for Fieldtrips
in Connecticut and Massachusetts: Northeast Section Geo-
logical Society of America Meeting 2012. State Geological
and Natural History Survey of Connecticut, Guidebook
Number 9. pp. A1–A18.
GODOY, L.C. AND G. LEONARDI. 1985. Direçoe
~s e comporta-
mento dos dinossauros da localidade de Piau, Sousa,
Paraíba (Brasil), Formaçaõ Sousa (Cretáceo inferior).
Coletânea de Trabalhos Paleontológicos, seçaõ 2, série
Geologia 27:65–73.
HAMMER, Ø. 2013. PAST Paleontological Statistics. Version
3.02. User’s Manual [internet]. Oslo: University of Oslo, Nat-
ural History Museum. 222 pp. Available from:
http://folk.uio.no/ohammer/past/past3manual.pdf
HITCHCOCK, E. 1836. Ornithichnology—Description of the foot
marks of birds, (Ornithichnites) on New Red Sandstone in
Massachusetts. American Journal of Science 29:307–340.
—1848. An attempt to discriminate and describe the animals
that made the fossil footmarks of the United States, and espe-
cially of New England. American Academy of Arts and Sci-
ences Memoir 3:129–256.
—1858. Ichnology of New England. A Report on the Sandstone
of the Connecticut Valley, Especially its Fossil Footmarks.
Boston: Commonwealth of Massachusetts, William White.
220 pp.
HUBERT, J.F., A.A. REED AND P. J . C ARREY. 1976. Paleogeography
of the East Berlin Formation, Newark Group, Connecticut
Valley. American Journal of Science 276(10):1183–1207.
HUBERT, J.F., P.E. FESESHBACH-MERINEY AND M.A. SMITH. 1992.
The Triassic-Jurassic Hartford Rift basin, Connecticut and
Massachusetts: Evolution, sandstone diagenesis, and hydro-
carbon history. The American Association of Petroleum
Geologists Bulletin 76(11):1710–1734.
IRBY, G.V. 1996. Paleoichnology of the Cameron Dinosaur
Tracksite, Lower Jurassic Moenave Formation, northeastern
Arizona. In: M. Morales, ed. The Continental Jurassic.
Flagstaff: Museum of Northern Arizona. pp. 147–166. (Bul-
letin 60.)
LOCKLEY, M. 1991. Tracking Dinosaurs: A New Look at an
Ancient World. Cambridge: Cambridge University Press.
238 pp.
LOCKLEY, M.G., K.J. HOUCK AND N.K. PRINCE. 1986. North
America’s largest dinosaur trackway site: Implications for
Morrison Formation paleoecology. Geological Society of
America Bulletin 97(10):1163–1176.
LOCKLEY, M.G. AND M. MAT SU KAWA. 1999. Some observations
on trackway evidence for gregarious behavior among small
bipedal dinosaurs. Palaeogeography, Palaeoclimatology,
Palaeoecology 150:25–31.
MCHONE, G. 2004. Great Day Trips to Discover the Geology
of Connecticut. Wilton: Perry Heights Press. 207 pp.
MEYERS, T.S. AND A.R. FIORILLO. 2009. Evidence for gregarious
behavior and age segregation in sauropod dinosaurs. Palaeo-
geography, Palaeoclimatology, Palaeoecology 274:96–104.
NICHOLS, G. 1999. Sedimentology and Stratigraphy. Malden:
Blackwell Science. 355 pp.
OLSEN, P.E. 1980. Fossil great lakes of the Newark Supergroup
in New Jersey. In W. Manspeizer, ed. Field Studies of New
Jersey Geology and Guide to Field Trips. New York State
Geological Association 52nd Annual Meeting Guidebook.
Newark: Rutgers University. pp. 352–398.
—1986. A 40-million-year lake record of early Mesozoic orbital
climactic forcing. Science 234(4778):842–848.
—1997. Stratigraphic record of the early Mesozoic breakup of
Pangea in the Laurasia-Gondwana rift system. Annual
Review of Earth and Planetary Sciences 25:337–401.
OLSEN, P.E. AND E.C. RAINFORTH. 2003. The early Jurassic
dinosaurian ichnogenus Anomoepus. In: P.M. LeTourneau
and P.E. Olsen, eds. The Great Rift Valleys of Pangea in East-
ern North America. Volume 2, Sedimentology, Stratigraphy,
Paleontology. New York: Columbia University Press. pp.
314–368.
OLSEN, P.E., J.B. SMITH AND N.G. MCDONALD. 1998. Type
material of the type species of the classic theropod footprint
genera Eubrontes, Anchisauripus and Grallator (Early Juras-
sic, Hartford and Deerfield Basins, Connecticut and Massa-
chusetts, U.S.A.). Journal of Vertebrate Paleontology
18(3):586–601.
OSTROM, J.H. 1972. Were some dinosaurs gregarious? Palaeo-
geography, Palaeoclimatology, Palaeoecology 11:287–301.
OWEN, R. 1842. Report on British Fossil Reptiles. Part II. In:
Report of the Eleventh Meeting of the British Association
for the Advancement of Science; Held at Plymouth in July
1841. London: John Murray. pp. 60–204.
RAINFORTH, E.C. 2005. Ichnotaxonomy of the fossil footprints
of the Connecticut Valley (Early Jurassic, Newark Super-
group, Connecticut and Massachusetts) [dissertation]. New
York: Columbia University. Available from: http://phobos.
ramapo.edu/~erainfor/pubs/RainforthPhD.pdf
ROACH, B.T. AND D.L. BRINKMAN. 2007. A reevaluation of coop-
erative pack hunting and gregariousness in Deinonychus
antirrhopus and other nonavian dinosaurs. Bulletin of the
Peabody Museum of Natural History 48(1):103–138.
RODGERS, J., COMPILER. 1985. Bedrock Geologic Map of Con-
necticut [map]. Connecticut Geological and Natural His-
tory Survey, Connecticut Natural Resources Atlas Series.
Prepared in cooperation with the U.S. Geological Survey.
Hartford, CT. 2 sheets. Available from: http://cteco.
uconn.edu/map_catalog/maps/state/Bedrock_Geologic_
Map_of_Connecticut.pdf
SCHUMACHER, B. AND M. LOCKLEY. 2014. Newly documented
trackways at “Dinosaur Lake,” the Purgatorie Valley
dinosaur tracksite. New Mexico Museum of Natural History
and Science Bulletin 62:261–268.
SMITH, J.B. AND J.O. FARLOW. 2003. Osteometric approaches to
trackmaker assignment for the Newark Supergroup ichno-
genera Grallator, Anchisauripus, and Eubrontes. In: P.M.
LeTourneau and P.E. Olsen, eds. The Great Rift Valley of
Pangea in Eastern North America. Volume 2, Sedimentol-
ogy, Stratigraphy and Paleontology. New York: Columbia
University Press. pp. 273–292.
SMITH, J.B. AND J.R. SMITH. 1996. Mt. Tom revisited: A new fos-
sil horizon at Dinosaur Footprint Reservation, Northamp-
ton, Massachusetts. Journal of Vertebrate Paleontology 16(3
suppl.):67A.
THOMPSON, N. 1996 June 23. Putting their foot in it: Dinosaurs
weren’t shy about leaving their tracks all over central Con-
necticut. The Hartford Courant, p. H1 (1 p.). Available from:
The Hartford Courant Archives (1764–1986); http://pqasb.
pqarchiver.com/courant/advancedsearch.html
THORPE, M.R. 1929. More Connecticut Valley footprints found
in North Branford, near New Haven, and their scientific
importance. The Yale Alumni Weekly 38(23):623–625.
THULBORN, T. 1990. Dinosaur Tracks. New York: Chapman and
Hall. 410 pp.
TOWN ACQUIRES REPTILE TRACKS. 1976 April 6. The Hartford
Courant, p. 17 (1 p.). Available from: The Hartford Courant
Archives (1764–1986); http://pqasb.pqarchiver.com/
courant/advancedsearch.html
WARNER, E. AND L. FOWLER, Sr. 1966. Industries. In: E. Burn-
ham et al., eds. A History of Middlefield: Written for the
Centennial Celebration 1866–1966. Portland, CT: The
Eaverly Printing Co. pp. 19–28.
WEEK-LONG ACTIVITIES START TODAY TO MARK MIDDLEFIELD’S
BIRTHDAY. 1966 May 8. Special, The Hartford Courant, p. 40A
(1 p.). Available from: The Hartford Courant Archives
(1764–1986); http://pqasb.pqarchiver.com/courant/advan
cedsearch.html
WEEMS, R.E. 2006. Locomotor speeds and patterns of running
behavior in non-maniraptoriform theropod dinosaurs. New
Mexico Museum of Natural History and Science Bulletin
37:379–389.
WENK, W.J. 1984. Seismic refraction model of depth of base-
ment in the Hartford Rift Basin, Connecticut and Massa-
chusetts. Northeastern Geology 6:196–202.
Bulletin of the Peabody Museum of Natural History 56(1) • April 2015
106
