taxonID	type	description	language	source
03EBA441FF9D844FC78FFA81F2CED197.taxon	description	has an elongate, triangular frontal with a long orbital rim (Figs. 1 a, 2). A prefrontal has not been identified with certainty in troodontids, although a small, slender bone along the orbital rim of the frontal may be that bone (Currie, 1985). The lacrimal suture encroaches onto the dorsal surface of the frontal, and ends caudally in a wall of bone. The dorsal surface of the frontal is concave in cross-section in the interorbital region, raised on both the midline and the orbital rim. A well defined ridge running from the medial edge of the frontoparietal suture to the deep, pit-like suture for the postorbital marks the anterior boundary of the supratemporal fenestra. As in ornithomimids, NMC 12355 and dromaeosaurids, the frontal provides very little area of bone for muscle attachment within the supratemporal fenestra.	en	Currie, P. J. (1987): Theropods of the Judith River Formation of dinosaur Provincial Park, Alberta, Canada. In: Currie P. J., Koster E. H. (Eds): Fourth Symposium on Mesozoic Terrestrial Ecosystems. Drumheller, Alberta: Tyrrell Museum of Paleontology: 51-60, DOI: 10.5281/zenodo.3676391
03EBA441FF9E844FC7EFFE07F2D5D543.taxon	discussion	The frontals of Struthiomimus altus (AMNH 5355) and Ornithomimus edmontonicus (ROM 851, Horseshoe Canyon Formation) are essentially identical to that of Dromiceiomimus samueli. Sues (1978) briefly described an indeterminate frontal in the collections of the National Museum of Canada (NMC 12355, Fig. 1 C) and referred it to the Theropoda. However, comparison with Mongolian specimens suggests that it may represent Erlicosaurus (Currie, in preparation), a genus that is currently regarded as a Late Cretaceous prosaurupod (Paul 1984). The frontal suture of an isolated caenagnathid parietal (TMP 81. 1 9. 25 2, Currie, in preparation) shows that NMC 12355 is not a caenagnsthid, but it still may turn out to be an elmisaurid or other theropod. This frontal is an elongate triangle, like those of troodontids and ornithomimids. A shallow, rostrodorsal sutural surface suggests that the prefrontal was present and in the same position as in ornithomimids. The caudolateral margin of the ventral suture of the lacrimal is a transverse wall of bone similar to that of Troodon. A longitudinal trough runs along the dorsal surface of the frontal between the midline and the orbital rim. A poorly defined ridge marks the rostral boundary of the supratemporal fenestra. Dromaeosaurid frontals (Figs. 1 d, 1 e, 3) are readily distinguished from those of other theropods. They are relatively shorter and broader than troodontid and ornithomimid frontals. In ventral view, the orbital rim is split rostrolaterally, and the lacrimal passes through this slot onto the dorsal surface of the bone. This is very different from the broad lacrimal suture on ventral surface of the frontals of Troodon and NMC 12355, but is comparable with this part of the frontolacrimal suture of tyrannosaurids. Rostrodorsally, the dromaeosaurid frontal has a squamose sutural surface for the nasal and prefrontal bones. In dorsal view, the postorbital process of the frontal diverges strongly from the rest of the orbital rim. The postorbital suture extends onto the caudodorsal surface of the postorbital process, and is not well defined. The frontal is only shallowly dished out in the interorbital region.	en	Currie, P. J. (1987): Theropods of the Judith River Formation of dinosaur Provincial Park, Alberta, Canada. In: Currie P. J., Koster E. H. (Eds): Fourth Symposium on Mesozoic Terrestrial Ecosystems. Drumheller, Alberta: Tyrrell Museum of Paleontology: 51-60, DOI: 10.5281/zenodo.3676391
03EBA441FF9F8449C78AFAB9F218D1A9.taxon	description	are the premaxillary teeth of a small tyrannosaurid. They are relatively common, and can be distinguished from the teeth of juvenile specimens of large tyrannosaurids by their lack of serrations and more gracile appearance. Gracile, small maxillary and dentary teeth with serrations have also been identified as a small, Judithian tyrannosaurid. It would appear that a Lancian theropod described by Molnar (1978) is in fact a small tyrannosaurid, and that this animal is the same as the tooth genus Aublysodon (K. Carpenter and R. E. Molnar, personal communication, 1986). It seems possible then that TMP 80.16.485 (Fig. 1 f) is Aublysodon or a closely related genus. It is conceivable that further preparation and study of the type specimen or Gorgosaurus sternbergi (AMNH 5664, Matthew and Brown 1923) will reveal that this is a valid species, and that this is the source of the aublysodont teeth.	en	Currie, P. J. (1987): Theropods of the Judith River Formation of dinosaur Provincial Park, Alberta, Canada. In: Currie P. J., Koster E. H. (Eds): Fourth Symposium on Mesozoic Terrestrial Ecosystems. Drumheller, Alberta: Tyrrell Museum of Paleontology: 51-60, DOI: 10.5281/zenodo.3676391
03EBA441FF9F844EC785FC83F2ABD53A.taxon	discussion	The orbital rim of the frontal is very short, and in some species is reduced to a slot passing between the lacrimal and postorbital (Fig. 1 g). The frontal-postorbital suture is expanded in all tyrannosaurids (Figs. 1 f, g, h). At the rostral end of the contact, the frontal develops a pronounced buttress with a posterolaterally oriented suture (Fig. 1 f), behind which the frontal is broadly overlapped by the postorbital. The relationship between the frontal and postorbital changes both ontogenetically and in more progressive tyrannosaurids however, and the contact becomes more elongate rostrocaudally and more vertical. A rostrodorsal process of the parietals separates the frontals posteriorly, and the sagittal crest extends onto the frontals. Tyrannosaurid frontals are essentially flat dorsally between the orbits. The temporal musculature extends far onto the dorssl surface of the frontal, its anterior boundary being a low sinuous ridge between the sagittal crest and the postorbital buttress.	en	Currie, P. J. (1987): Theropods of the Judith River Formation of dinosaur Provincial Park, Alberta, Canada. In: Currie P. J., Koster E. H. (Eds): Fourth Symposium on Mesozoic Terrestrial Ecosystems. Drumheller, Alberta: Tyrrell Museum of Paleontology: 51-60, DOI: 10.5281/zenodo.3676391
03EBA441FF9F844EC786FD9CF1FFD313.taxon	description	is a more robust animal than Saurornitholeates langstoni, and is much rarer (Table 1). The lacrimal slot (Fig. 1 e) is well developed. In both AMNH 5356 and NMC 12349, the orbital rim is squared off and rugose, suggesting the presence of an additional bone on the orbital rim, similar to that of Troodon. If this is the case, it may be a palpebral. An examination of Dromaeosaurus teeth from Dinosaur Provincial Park suggests that more than one species was present in Judithian times (Currie, Rigby and Sloan, in preparation). It may be significant then that NMC 12349 is more robust than AMNH 5356, and that the ridge marking the anterior limit of the supratemporal fenestra is more strongly curved. As in tyrannosaurids, the posterodorsal surfaces of the paired frontals separate on the midline for an anteromedial process of the fused parietals (Fig. 1 e) in NMC 12349.	en	Currie, P. J. (1987): Theropods of the Judith River Formation of dinosaur Provincial Park, Alberta, Canada. In: Currie P. J., Koster E. H. (Eds): Fourth Symposium on Mesozoic Terrestrial Ecosystems. Drumheller, Alberta: Tyrrell Museum of Paleontology: 51-60, DOI: 10.5281/zenodo.3676391
03EBA441FF9F844EC786FF64F170D212.taxon	description	is the most common small theropod in the Judith River Formation of Dinosaur Provincial Park, judging from the number o: frontais (Tsble l) and teeth (Currie, Rigby and Sloan, in preparation) recovered. In contrast with Dromaeosaurus, the medial prong of the nasal does not extend as far caudally over the frontal as the more lateral prong. The slot that the lacrimal passes through the frontal to contact the prefrontal. is relatively small (Fig. 1 d). The frontal is somewhat bulbous caudally where it curves posteroventrally to meet the parietal. A faint, sigmoidally curved ridge runs rostrolaterally onto the front margin of the postorbital process, and marks the anterior limit of the supratemporal fenestra. Unlike Dromaeosaurus, the portion of the frontal within the supratemporal fenestra is posterodorsally concave, and even forms a deep pit in some specimens (TMP 86.77.57, Fig. 1 d).	en	Currie, P. J. (1987): Theropods of the Judith River Formation of dinosaur Provincial Park, Alberta, Canada. In: Currie P. J., Koster E. H. (Eds): Fourth Symposium on Mesozoic Terrestrial Ecosystems. Drumheller, Alberta: Tyrrell Museum of Paleontology: 51-60, DOI: 10.5281/zenodo.3676391
03EBA441FF988449C7E3FDE8F2EED3FB.taxon	discussion	Although frontals of caenagnathids are currently unknown from Dinosaur Provincial Park, one can predict that they will be bulbous and lightly built, like those of Oviraptor. The isolated parietal (TMP 81.19.252) shows that the frontals are separated from each other caudally by a rostral process of the fused parietals, and that the frontal broadly overlaps the parietal posterolaterally.	en	Currie, P. J. (1987): Theropods of the Judith River Formation of dinosaur Provincial Park, Alberta, Canada. In: Currie P. J., Koster E. H. (Eds): Fourth Symposium on Mesozoic Terrestrial Ecosystems. Drumheller, Alberta: Tyrrell Museum of Paleontology: 51-60, DOI: 10.5281/zenodo.3676391
03EBA441FF988449C7FDFE28F1EDD268.taxon	description	frontals are characterized by the presence of a prefrontal socket, the reduction of the orbital rim to a notch, and the retention of a relatively short (rostrocaudally), overlapping suture for the postorbital (Fig. 1 g). immature frontals of Gorgosaurus libratus can be distinguished from that of cf. Aublysodon by their relatively greater thickness and width for a given length. in Daspletosaurus torosus, the shape of the frontal has been changed by the enlargement of the lacrimal and postorbital, causing an increase in the posterior width of the frontal (Fig. 1 h), and a lengthening of the postorbital suture.	en	Currie, P. J. (1987): Theropods of the Judith River Formation of dinosaur Provincial Park, Alberta, Canada. In: Currie P. J., Koster E. H. (Eds): Fourth Symposium on Mesozoic Terrestrial Ecosystems. Drumheller, Alberta: Tyrrell Museum of Paleontology: 51-60, DOI: 10.5281/zenodo.3676391
