A Third Canid from the Hagerman Fossil Beds (Hagerman Fossil Beds National Monument), Hagerman, Idaho, USA Kari Alyssa Prassack,
[email protected], Hagerman Fossil Beds National Monument, 221 N. State Street, Hagerman ID, USA A
A Quick Look
D
Who—Canis c.f. lepophagus What—HAFO 21175, a left dentary broken anterior to the p3 with the p3–m3 intact and part of the masseteric fossa retained. The p3-4 show mild wear, the m1 exhibits mild-moderate wear and the m2-3 moderate wear. Referred, HAFO 23808, an unworn, isolated, right m1. Where—Hagerman Fossil Beds National Monument (HAFO), south-central Idaho, USA. HAFO 21175 comes from Locality 042 (919m a.s.l) approximately 5 km south of the Smithsonian Horse Quarry. HAFO 23808 comes from an un-numbered locality (952m a.s.l) less than 2km south of the Horse Quarry. When— Blancan Land Mammal Age, early-middle Pliocene. The Hagerman Fossil Beds date from ~4.2 to 3.0 Ma
B Canid Evolution
C
10 mm
Figure 1. HAFO 21175 shown in A: labial B: lingual, and C: occlusal view. D: HAFO 23808 in labial (top), occlusal (middle), and lingual (bottom) view.
• Canids first appear in the late Eocene of North America • Three subfamilies: Hesperocyonidae (extinct), Borophaginae (extinct), and Caninae • Caninae (true canids, including wolves, jackals, coyotes, dingos, fox and dog) appear in the early Oligocene • Canines and Borophagines co-existed during the Miocene and part of the Pliocene • Pliocene borophagines may have served an ecological role similar to spotted hyenas • Canis ferox, the earliest example of Canis, is established by the late Hemphillian (late Miocene/early Pliocene) • Canis lepophagus occurs throughout the Blancan age of the Pliocene but is largely restricted to the middle and late Blancan • C. ferox and C. lepophagus are morphologically similar and coyote-sized • Tedford et al. (2009) subesequently reassigned many of the smaller specimens of C. lepophagus to C. ferox
B
Hagerman’s Canids
A
Specimens— HAFO 21175 and 23808 were compared to Eucyon davisi (F:AM 63009-B; F:AM 49294), Canis thooides (F:AM 63092), Canis edwardii (USNM 184126) and to the following:
Canis sp.
Barber Ranch, Glenns Ferry Formation, late Blancan, ID—LACM (CIT) 1343 Grand View local fauna, Glenns Ferry Formation, late Blancan, ID— LACM (CIT) 1246 Cita Canyon, early late Blancan, TX—CWT 560, CWT 1027d, CWT 2617 Lisco Member, Broadwater Formation, middle Blancan, NE—UNSM 4260, USNM 26116, USNM 26113 Jackass Butte, Glenns Ferry Formation, late Blancan, ID— UOMNH 16416, UOMNH 30069
Specimen Repository Abbreviations—WTUC (CWT); Panhandle-Plains Museum, West Texas University, F:AM; Frick Collections, American Museum of Natural History, HAFO; Hagerman Fossil Beds National Monument, IMNH; Idaho Museum of Natural History, UMMP; University of Michigan Museum of Paleontology, USNM; United States National Museum of Natural History, Smithsonian Institution, UNSM; University of Nebraska State Museum; UOMNH, University of Oregon Museum of Natural History Specimen Measurements—Measurements included dentary depth (D1) taken along the base of the m1 paraconid, dentary width taken perpendicular to the horizontal ramus (PW) and parallel to it at the point of the paraconid (DW1); p3 shape (P3S); p4 shape (P4S); m1 shape (M1S); m1 height in relation to depth of mandible (MH:D1); relative grinding area (RLGA), which is the square root of the total grinding area from the m1 talonid through posterior edhge of m3 alveolus; arcade length (ARC), taken from the p3 anterior to m3 posterior; and relative blade length (RBL), trigonid length in relation to the total length of the m1. Measurements follow Van Valkenburgh (1988), Van Valkenburgh and Wayne (1994), and Tedford et al (2009). Measurements were taken using an electronic digital caliper (accuracy to 0.01 mm) with serial data output capacity and rounded to the nearest 0.01 mm. Each measurement was repeated three times and an average was used (Table 1).
10 mm
C
Figure 2. A: UNSM 26116, Canis lepophagus from the late Blancan Lisco Member of Broadwater Formation(top), HAFO 21175 (middle), and UMMP 53910, Canis ferox from the early-middle Blancan Hagerman Fossil Beds (bottom). UMMP 53910 has been inverted for comparative purposes. B : Lingual view of HAFO 18771 (top), one of the larger Canis ferox specimens from Hagerman, compared to HAFO 21175 (bottom). C: Ventral view of the horizontal ramus of HAFO 4925, Canis ferox, compared to HAFO 21175.
Materials and Methods
Canis lepophagus
HAFO 21175, robust, posteriorly expanded premolars; p4 with a large, second posterior cuspid; p4 conid extends above paraconid; robust m1; posteriorly-directed paraconid; deep, robust horizontal ramus; and a deep masseteric fossa with clearly delineated anterior and ventral margins align it with C. lepophagus. The premolars lack the medial restriction observed in C. ferox. The hypoconid and entoconid are worn, but the base of the hypoconid is broad and connects to the entoconid by a transverse ridge that is more commonly obsered in C. lepophagus. Some dental measurements overlap with larger specimens of C. ferox. However, the robust p3, p4 and m1 align in width and shape with the largest C. lepophagus specimens. In C. lepophagus, a transverse crest is sometimes observed connecting the metaconid and hypoconid. This trait is absent in C. ferox, instead, a distinct crest forms between the hypoconid and the anterior-buccal edge of the paraconid. In the HAFO specimens, the crest attaches to the anterio-medial face of the paraconid, restricting the talonid basin, but to a lesser degree than what is seen in C. lepophagus. Other differences include a deeper mandibular ramus exhibiting a greater buccal-lingual breadth below the carnassial; p4 less crowded against the m1; and posterior face of the protoconid with a rounded rather than facet-like face. HAFO 23808 is as in HAFO 21175, but possesses a deeper, more restricted talonid basin and expanded hypoconuli, placing this younger specimen more in line with C. lepophagus. HAFO 21175 measurements exceed that of Canis lepophagus for dentary depth (D1) and breadth (PW, DW1). MH:D1 measurememnts further show that this was a robust-jawed canid, though. Additional dentary measurements, not included here for the dentary, show that HAFO 21175’s horizontal ramus maintains its thickness through to the mandibular fossa. Molariform shape exceeds that of C. lepophagus but the arcade length falls within range for that canid. Grinding area is low, while the shearing area (relative blade length) is high. This combination of traits suggests a strong bite needed for taking down larger prey, but without the bone-cracking capabilities of Pliocene borophagines.
Discussion
• Tedford et al. (2009) reassigned Hagerman’s Canis lepophagus (Bjork, 1970) to C. ferox noting that that it was smaller and less robust that C. lepophagus from Cita Canyon (Type Locality) • Tedford et al. (2009) based this on specimens housed in the NMNH and UMMP collections • Canids from HAFO’s collections (housed on the Monument) were not included in the Tedford et al. (2009) study • HAFO 21175 was collected by HAFO staff in the summer of 2009, while HAFO 23808 was collected in 2005. • Canis ferox is relatively common throughout Hagerman‘s deposits • Large, robust-jawed Borophagus c.f. hilli is very uncommon and limited to younger deposits
Canis ferox Various quarries, Big Sandy Formation, late Hemphillian, AZ— F:AM 63061, F:AM 63032, F:AM 63035 Hagerman Fossil Beds, Glenns Ferry Formation, middle Blancan, ID—USNM 25131, USNM 25132; UMMP 53910, UMMP 4523, HAFO 18771, HAFO 20192, IMNH 4937, IMNH 493
Results
References Bjork, P. R. 1970. The Carnivora of the Hagerman local fauna (late Pliocene) of southwestern Idaho. Transactions of the American Philosophical Society, New Series 60(7) 3–54.
The Hemphillian-Blancan aged Canis ferox is largely comprised of plesiomorphic traits shared with the the smaller late Clarnedonian-Hemphillian Eucyon davisi and the larger Blancan C. lepophagus. The largest specimens of Canis ferox overlap in size with smaller specimens of Canis lepophagus, but HAFO C. ferox are smaller and more gracile(Tedford et al., 2009; Table 1). The depth and robusticity of the mandibular ramus and robustness of the molariform dentition of HAFO 21175 and 28308 are in line with the largest of C. lepophagus specimens, and this alone preclude these specimens from being assigned to C. ferox. Canis lepophagus exhibits intraspecific variability, only some of which can be explained by sexual dimorphism (Tedford et al., 2009). Morphological differences observed in the HAFO specimens may reflect this variation, and the robusticity of the dentray suggests a male, but the possibility of this being a distinct species cannot be ruled out at this time. This canid is referred to here as Canis c.f. lepophagus, based on the shared traits as described above and the known presence of this taxon in Idaho’s medial Blancan Grandview fauna. Carnivorans are relatively common at Hagerman but larger carnivorans are rare and stratigraphically restricted; Borophagus c.f. hilli is limited to younger deposits (~3.4-3.2 Ma). The ecological role of this canid was likely intermediate between the smaller, more gracile C. ferox and the bone-crushing Borophagus c.f. hilli, with these three taxa’s ecologies mirroring what is seen in East Africa between black-backed jackal, wild dog, and spotted hyena. HAFO 21175 occurs below Bed G (3.79 Ma) while HAFO 23808 is higher up in the sequence at between 3.4 and 3.6 Ma. 40AR/30AR dates for sili Monument are based on the work of Hart and Brueske (1999). Refinement of these dates is in progress (Walkup et al., 2016) and will provide a clearer time line for this canids occurence at Hagerman as well as help to discern temporal and spatial shifts in Hagerman’s carnivoran guild. This canid adds to Hagerman’s alreadyrich carnivoran guild which includes two ursids, four felids, a mephitid, at least eight mustelids, and two other canids (Bjork, 1970; Samuels et al., 2009; Prassack, 2016).
Hart, W. K. Brueseke, M.E. 1999. Analysis and dating of volcanic horizons from Hagerman Fossil Beds National Monument and a revised interpretation of eastern Glenns Ferry Formation chronostratigraphy: a report of work accomplished and scientific results. National Park Service Report 1443A:1–37. Prassack, K.A., 2016. Lontra weiri sp. nov., a Pliocene river otter (Mammalia, Carnivora, Mustelidae, Lutrinae) from the Hagerman Fossil Beds (Hagerman Fossil Beds National Monument), Idaho, U.S.A. Journal of Vertebrate Paleontology, 36(4) DOI: 10.1080/02724634.2016.1149075.
Acknowledgements
Samuels, J.X., Meachen-Samuels, J.A., Gensler, P.A. 2009. The first mid-Blancan occurrence of Agriotherium (Ursidae) in North America: a record frm Hagerman Fossil Beds National Monument. Journal of Vertebrate Paleontology, 83(4) 597-603. Tedford, R.H., Wang, X., Taylor, B.E. 2009. Phylogenetic systematics of the North American fossil Caninae (Carnivora: Canidae). Bulletin of the American Museum of Natural History, No. 325, 218pp. Van Valkenburgh, B. 1989. Carnivore dental adaptations and diet: a study of trophic diversity within guilds. Pp. 410-436, in, Gittleman, J. L. (Ed.), Carnivore Behavior, Ecology, and Evolution, Vol. I, Cornell University Press. Van Valkenburgh, B., Wayne, R. K. 1994. Shape divergence associated with size convergence in sympatric East African jackals. Ecology, 75(6):1567-1581. Walkup, L. C., Prassack, K. A., Hart, W. K., Wan, E. 2016. Tephrochronology and stratigraphy of silicic and basaltic volcanic ash layers at Hagerman Fossil Beds National Monumeet, Idaho, USA. Abstract #149041, 49th Meeting of the American Geophysical Union, San Francisco, CA.
This research was conducted as federal employee working at Hagerman Fossil Beds National Monument (National Park Service). I am grateful to my park for facilitating this research and for sending me here to present my results. Special thanks to AMNH, UMMP, UOMNH, USNM, UNSM, IMNH amnd WTUC) and their staff who loaned out fossils for this research. Their time and willingness to assist are greatly appreciated, so a great big THANK YOU to Adam Rountrey, Amanda Millhouse, Sam McLeod, Edward Davis, Nick Famoso, Gerald Schultz, Veronica Arias, Mary Thompson, Lindsay Jurgielewicz, George Corner, and everyone else involved with the loans. Special thanks also to the 2005 and 2009 HAFO field crews who collected HAFO 21175 and 28308. Kelli Tolleson, one of my awesome Geoscientists-in-the-Parks interns, assisted with photography and packing of specimens.
