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Fossil Mammoths from Santa Cruz Island, California
Abstract
Mammoth remains on Santa Cruz Island, one of the four Northern Channel Islands of California, are very sparse, in marked contrast to those reported from Santa Rosa and San Miguel Islands of the same island group. A probable major reason for this scarcity is that Quaternary deposits are greatly restricted on Santa Cruz Island. It is proposed, contrary to popular opinion, that fossils found on Santa Cruz Island were derived from animals which died on the island, and were not transported there by humans. Reasons for this conclusion are that the size and geological context of the fossils are similar to those of the largest mammoth fossils of Santa Rosa Island, and that, in spite of extensive investigations by many persons, mammoth remains have not been found in middens, either on the islands or on the adjacent mainland.
... " In some instances, including a poorly documented locality at Running Springs on San Miguel Island, mammoth bones show clear evidence of burning. Research by Glassow (1980), Cushing et al. (1984, 1986), Wendorf (1982) , and others has suggested that these associations are probably the result of overturned burning trees or chemical changes in the soil rather than human cooking of mammoth remains. ...
... A classic example of how taphonomic studies have improved our interpretations of Channel Islands archaeology is Orr's (1968) ardent assertion that he had identified associations of human artifacts or agency with Pleistocene fauna, including pygmy mammoth remains dating to more than 40,000 years. Careful taphonomic studies of Orr's evidence suggests, however, that his fire areas were natural features caused by burning trees or chemical interactions in the soils (see Glassow, 1980; Cushing et al., 1984 Cushing et al., , 1986) and that other spatial associations were actually in secondary erosional exposures. Recent analysis of a bald eagle nest on Santa Rosa Island has also demonstrated that eagles transported large abalone shells and other marine fauna found in archaeological sites to their nests (Erlandson et al., 2003; Collins et al., 2005). ...
Inhabited by humans for over 12,000 calendar years, California's Channel Islands contain thousands of archaeological sites, ranging from dense shell middens and villages to small lithic scatters and camps. Similar to many islands around the world, the Channel Islands have a dearth of burrowing animals and limited historical development leading to generally good preservation of archaeological constituents and relatively high stratigraphic integrity. Despite these favorable preservation conditions, numerous natural and cultural processes have impacted the island's archaeological record. Channel Islands archaeologists, however, have given relatively limited attention to the effects of taphonomic and formation processes. The authors provide an overview of taphonomic and formation processes affecting Channel Islands archaeology, illustrating the importance of regional taphonomic syntheses in the management, preservation, and interpretation of archaeological sites. These data also demonstrate the significance of detailing formation processes in islands and other areas where burrowing rodents and other disturbances are thought to be absent or limited. © 2006 Wiley Periodicals, Inc.
... On Santa Cruz Island, a study of Holocene sediments helps chronicle the effects of overgrazing and ranching ( Perroy et al. 2012). The remains of mammoths have also been recovered and reported from Santa Cruz Island, although these types of remains are less abundant on Santa Cruz Island than on Santa Rosa and San Miguel Islands ( Cushing et al. 1984). Similarly, plant macrofossils from Cañada de los Sauces on Santa Cruz Island help characterize Pleistocene plant communities on the Northern Channel Islands ( Chaney and Mason 1930). ...
Santa Cruz Island contains a remarkable array of cultural and biological resources and a rich tradition of research across the social and biological sciences and humanities. Given dramatic changes in climate forecast in the coming decades of the Anthropocene, however, many questions remain about the sustainability and future of island ecosystems and cultural resources. Here, we focus on a new interdisciplinary initiative, Island Rediscovery (IR), that was the subject of 2 recent workshops. Drawing on a variety of disciplines and approaches, IR seeks to utilize research on Santa Cruz Island's past and present to help better prepare for the future and plan for forecast change, an approach we call horizon scanning. Our focus is on archaeology, history, and paleobiology, 3 disciplines that offer deep historical perspectives critical to understanding modern ecosystems and preparing for future variability. We outline the potential of deep historical research, offer core questions that can guide future work, and document the need for a large synthetic database and digitization effort. By integrating the historical and biological sciences, the historical ecological approach of IR offers a new framework for managing the resources of the California Islands by providing baselines and context for management, documenting the range of ecological variability through deep time, and helping establish desired future conditions.
... Sample preparation follows methods outlined by Ludwig et al. (1992) ) where fossil mammoth remains have been located. Mammoth locality data from Johnson (1979); Cushing et al. (1984); Agenbroad (1998Agenbroad ( , 2012; Agenbroad et al. (1999), and the present study. ...
Fossils of Columbian mammoths (Mammuthus columbi) and pygmy mammoths (Mammuthus exilis) have been reported from Channel Islands National Park, California. Most date to the last glacial period (Marine Isotope Stage [MIS] 2), but a tusk of M. exilis (or immature M. columbi) was found in the lowest marine terrace of Santa Rosa Island. Uranium-series dating of corals yielded ages from 83.8 ± 0.6 ka to 78.6 ± 0.5 ka, correlating the terrace with MIS 5.1, a time of relatively high sea level. Mammoths likely immigrated to the islands by swimming during the glacial periods MIS 6 (~ 150 ka) or MIS 8 (~ 250 ka), when sea level was low and the island–mainland distance was minimal, as during MIS 2. Earliest mammoth immigration to the islands likely occurred late enough in the Quaternary that uplift of the islands and the mainland decreased the swimming distance to a range that could be accomplished by mammoths. Results challenge the hypothesis that climate change, vegetation change, and decreased land area from sea-level rise were the causes of mammoth extinction at the Pleistocene/Holocene boundary on the Channel Islands. Pre-MIS 2 mammoth populations would have experienced similar or even more dramatic changes at the MIS 6/5.5 transition.
... The discovery of the first mammoth tusk on Santa Cruz Island in 1985 (also see Cushing et al. 1984) led us to review critically the original publications of island mammoth dates and the conclusion presented here. We believe this review is complete and note that we did not extend it to secondary citations (some of these are not accurate or are confusing) or to other dates which are not published in edited journals. ...
We report the first mammoth tusk found (1985) on Santa Cruz Island, California. The tusk was secondarily deposited in alluvium of a former Pleistocene streambed. Wood in contact with the tusk radiocarbon dated at 10,290 ± 100 14 c yr B.P. (AA-1268). As this date obviously was equivocal relevant to the age of the tusk, we reviewed all dates published for mammoth fossils on the Northern Channel Islands. We conclude all of these dates also are equivocal. The reasons for this conclusion are discussed.
... The striking morphologies of island mammals have long attracted attention (Darwin, 1859; Wallace, 1880; Carlquist, 1974). Such remarkable island dwarfs as the elephants of Mediterranean islands (Sondaar, 1977) and mammoths of the Channel Islands of California (Cushing et al., 1984; Roth, 1990 ) have long fired the imagination of biologists and inspired numerous searches for explanations . Similarly, although cases of island gigantism are perhaps not as dramatic as those of dwarfism, they are none the less common and discussed by biologists. ...
Morphological relationship among sympatric animal species have often been seen as indirect evidence for competition. Many early ecomorphological studies revealed patterns that were taken as indicating character displacement and character release, driven by competition or lack thereof. These patterns may result from a coevolutionary morphological response or from species sorting according to size. Thus, the relationship between morphology and competition may be crucial for understanding both the morphological evolution of animals and the role of competition in structuring communities. Some earlier research perceived as indicating morphological relationships conditioned by interaction of species was conducted on mammals, particularly carnivores. Subsequent criticism in the ecological literature demonstrated that many of the perceived patterns could not be statistically confirmed, thus calling into question this line of evidence for competition. More recent ecological literature relies on strong statistical analyses and careful consideration both of guild composition and of which morphological traits should be examined. This literature, resting largely on mammals, includes several cases that suggest a coevolutionary morphological response to interspecific competition. These studies have focused on the thropic apparatus directly related to food procurement by mammals — the teeth. Island mammals often show striking morphological patterns, some of which have been interpreted as resulting from release from competition with mainland species that have not reached islands. However, few of these patterns were critically evaluated to demonstrate their support for the hypothesis of character release. Despite several decades of interest and research, many questions regarding competitively induced morphological patterns remain unresolved and require further research. Mammals are especially promising subjects for such researh.
... d All dates were calibrated using CALIB 5.0.2 (Stuiver and Reimer, 1993; Stuiver et al., 2005 morphologic data do not provide absolute ages, the fossil and archaeological records supply the most direct means of documenting the chronology of island fox dispersal. Numerous paleontological projects have been conducted on the Channel Islands, including research in paleontological and archaeological deposits at Daisy Cave (CA-SMI-261) on San Miguel (Guthrie, 1980; Walker, 1980; Erlandson et al., 1996 ), late Pleistocene and Holocene deposits at Arlington Springs (CA-SRI-173) on Santa Rosa (Johnson et al., 2002), late Pleistocene localities on San Miguel and Santa Rosa (Guthrie, 1993Guthrie, , 1998Guthrie, , 2005), late Pleistocene deposits on Anacapa (Lipps, 1964), and several mammoth localities on Santa Rosa, San Miguel, and Santa Cruz (Orr, 1968; Cushing et al., 1984; Gray and Harz, 1998; Agenbroad , 2002b Thaler, 1998; Agenbroad et al., 2005). These projects have yielded faunal assemblages that include abundant avian materials, extant and extinct micro-mammals, reptiles and amphibians, and mammoths (Guthrie, 1980Guthrie, , 1993 Walker, 1980;). ...
The island fox (Urocyon littoralis) is one of few reportedly endemic terrestrial mammals on California's Channel Islands. Questions remain about how and when foxes first colonized the islands, with researchers speculating on a natural, human-assisted, or combined dispersal during the late Pleistocene and/or Holocene. A natural dispersal of foxes to the northern Channel Islands has been supported by reports of a few fox bones from late Pleistocene paleontological localities. Direct AMS 14C dating of these “fossil” fox bones produced dates ranging from ∼ 6400 to 200 cal yr BP, however, postdating human colonization of the islands by several millennia. Although one of these specimens is the earliest securely dated fox from the islands, these new data support the hypothesis that Native Americans introduced foxes to all the Channel Islands in the early to middle Holocene. However, a natural dispersal for the original island colonization cannot be ruled out until further paleontological, archaeological, and genetic studies (especially aDNA [ancient DNA]) are conducted.
Schumann et al. (2016) presented a field assessment of late Pleistocene to Holocene fluvial sediments preserved in the valleys of Santa Rosa Island, California. This is a rigorous study, based on stratigraphic descriptions of 54 sections and numerous radiocarbon ages. The paper makes important contributions that we would like to highlight, but other parts of the paper rely upon overly simplistic interpretations that lead to misleading conclusions. In one case, a conclusion of the Schumann et al. paper has important management implications for Santa Rosa Island and similar locations, compelling us to discuss and qualify this conclusion.
Willard F Libby’s research, leading to the discovery of radiocarbon dating, was principally carried out at the University of Chicago after World War II with his main collaborators, E C Anderson and J R Arnold. At the behest of Libby, A V Grosse and his collaborators at the Houdry Process Corporation demonstrated the existence of radiocarbon in nature by concentrating the isotope from a source of biogenic methane. A Committee on Carbon-14 was formed from members of the American Anthropological Association and the Geological Society of America to select a significant slate of samples for dating. Committee members were Frederick Johnson, Donald Collier, Richard Foster Flint and Froelich Rainey, who all assisted Libby with advice and dating priorities. The basic technique for measuring radiocarbon was solid carbon dating, which Libby described in detail in his book entitled “Radiocarbon Dating” and two updated editions. Typically, samples were counted for 48 hours to accommodate the large numbers submitted. All radiocarbon dates obtained prior to the fall of 1951 by Libby’s original research team are listed in his publications (Libby 1952, 1955, 1965).
Pleistocene areas of red sediments and carbonized vegetation on the Northern Channel Islands, California, have in the past been interpreted as caused by fires of either natural or human origin. Some are associated with darkened mammoth and bird fossils, and these fossils have been considered as having been burned by early man. Reevaluation of these so-called “fire areas” indicates that the above phenomena are the result of low-temperature (≤100°C), nonheating processes occurring in groundwater. Evidence for this conclusion is derived from field observations on fossil carbonized vegetation, and the geology of the areas. Additional evidence derives from experiments on the red sediments and fossil wood, X-ray diffraction analyses, magnetic analyses, studies on the clay minerals smectite and illite, and the demonstration that fossil mammoth bone contains sufficient Fe and Mn to account for their discoloration. Much of the carbonization of vegetation probably occurred in water rather than in fire. Radiocarbon dates from the islands will probably need to be reevaluated. These data provide evidence contrary to the concept of the occurrence of significant fires, either natural or set by early man, on the Northern Channel Islands.
Mammoth remains have been known from the northern Channel Islands of California since 1856. Initially, it was considered that there were several species of mammoths on the islands. It has now been determined that there are only two species: 1) Mammuthus exilis, the island pygmy mammoth, and 2) Mammuthus columbi, the giant, continental (mainland) mammoths which were the ancestral mammoths from which M. exilis was derived. Discovery and recovery of the most complete skeleton of M. exilis, in 1994 prompted new research efforts and a numerical chronology for the pygmy mammoths, ranging from 11,030 BP to greater than 200,000 a by U/Th (Uranium/Thorium). Little attention had been paid to the chronology of the less abundant M. columbi remains. Uranium/Thorium dates on two M. columbi teeth yielded dates of 28,000 ± 2000 a, and 64,500 + 7400/−6900 a. If the U/TH dates are valid, they indicate a long history of shared island occupation, with M. exilis, or repeated migrations of M. columbi from the mainland to the islands. No M. exilis remains have been discovered on the mainland. In 2009 additional efforts to date the Columbian mammoth remains were initiated, to ascertain whether they were: 1) contemporary with the pygmy mammoths; 2) represented remnants of the founding population; or 3) represented late migration from the North American mainland.
The dentition of an elephant (fossil or extant) can yield clues to the animal's age species identity, provided the teeth are correctly identified. Identifying the serial category of elephant teeth is difficult because the size, shape and position of each tooth changes throughout life, as the teeth form, erupt, wear and move throught the jaw. In the present study, teeth from over 100 museum specimens of the Asian elephant (Elephas maximus) were the basis for establishing size ranges for cheek teeth in six serial categories (designated by Roman numerals I to VI). Although the teeth vary greatly and overlap in their dimensions, reliable identifications (as well as estimates of an individual's age in years) can be obtained using three or more measurements. An appreciation for dental variability in Elephas maximus will demand a re-evaluastion of frequently-cited examples of macroevolutionary patterns within the Elephantidae.
Anacapia is a geologic province which forms the southern boundary of the Santa Barbara Embayment and the northern limits of an old, often emergent, land mass -Catalinia. It embraces San Miguel, Santa Rosa, Santa Cruz, and Anacapa islands as well as the western part of the Santa Monica Mountains (Reed and Hollister, 1936). A study of the geology and evolution of the Northern Channel Islands, lying as they do on the southern edge of the Transverse Ranges (fig. 1) of California, has long held the interest of natural historians, both geologic and biologic. The Transverse Ranges as a whole form an anomalous feature to the general north-south trending structures of western North America. The Murray Escarp-ment, trending westward 1,900 miles out to sea, is believed to be a structural extension of this continental anomaly. This east-west trend terminates to the east against the great San Andreas fault system and the San Bernardino Range. Not only is it of interest for its obvious structural significance as it is related to one of the great features of the earth's crust, but this transverse feature also has strong biogeographical implications, having roots per-haps as far back as early Mesozoic time. With the progressive provincialization of marine faunas during the Cenozoic (Smith, 1919), these east-west trending mountain ranges, at times partly-submerged, partly emerged, served as the limits on more than one occasion for new biogeographic provinces (Kleinpell and Weaver, 1963), some of which became distinctive and conspicuous life areas in the middle and late Cenozoic. Thus the Transverse Ranges serve as a focal point of considerable significance not only for structural but for biogeographic studies as well. In fact, these two fields, tectonics and chorology, are rather intricately interrelated, though perhaps more directly through intermediate climatological phenomena. 13 The purpose of this paper is to summarize for the Symposium the paleogeographic implications of the available geologic data for the southern fringe of the Transverse Ranges -the Northern Channel Islands. Realizing that members of the Symposium are primarily interested in Cenozoic migratory land routes to the is-lands, it should be stated at the outset that present-day Anacapia offers a paucity of evidence for Cenozoic connections to the mainland. In general, ancient migratory routes are best delineated by the land animals and plants of the time. With but two excep-tions, the late Pleistocene to sub-Recent dwarf mammoths and the Recent biota of the Northern Channel Islands, such organisms are not known to be preserved. The Cenozoic land masses that are needed for faunal migrations to the islands are inferred from: (1) the presence of continental deposits; (2) the absence of de-posits representing major intervals of time, thus permitting the inference that the land was emergent during at least part of the time represented by the hiatus: (3) the fossil and mineralogical composition, texture, and structure of the marine and non-marine sedimentary rocks, which permit ecologic inferences; and (4) the gross structural framework of the province along which any oro¬ genic (mountain building) forces must have operated. The fore-going types of data are available from the literature cited and from recent unpublished work by the authors. Anacapia is an east-west trending physiographic unit with much of its lower elevations flooded by the Recent seas. Its pre-Tertiary, perhaps Mesozoic, origin is faintly reflected in the metamorphic and granitoid rocks of unknown, but pre-Cenozoic, age which are exposed on Santa Cruz Island and in the Santa Monica Mountains. It is dominated by sedimentary and volcanic rocks of Cretaceous to Miocene age and capped by late Pleis-tocene terrace formations. Rock exposures on the islands are notable for their complete lack of Pliocene deposits. The pre-Pliocene shales, sandstones, conglomerates, and volcanics are conspicuous for their lateral variation and discontinuity. Areas of post-Eocene erosion and deposition, especially in Catalinia, appear to have been uplifted and depressed mainly by block fault-ing of the basin and range type, i.e., similar to the basins and ranges common in Nevada (fig. 2). Such deformation began in Oligocene time and continued intermittently through the rest of the Cenozoic Era. Many of the blocks reversed their relative vertical positions during this time (Corey, 1954: Emery, 1954). 1. More information is known than is available to the author, since much data involving the off-shore area are of an industrial and thus confidential nature.
Pygmy proboscidean remains of Mammuthus exilis occur abundantly in late Quaternary deposits on the Northern Channel Islands, California. On the assumption that ancestral elephants could not have swum to the islands and must therefore have walked out, various land bridges have been hypothesized that link the northern islands to the mainland by a peninsula. Geological evidence for a land bridge, however, is lacking, and new evidence shows that elephants are excellent swimmers and skilled at crossing watergaps. The Santa Barbara Channel was narrowed to only 6 km during glacially lowered sea levels. Modern elephants swim much further, and at speeds ranging from 0.96–2.70 km/hr. Motives for California elephants to cross Pleistocene watergaps are inferred from motives that lead modern elephants in Asia and Africa to cross watergaps. These are the visual and olfactory sensing of islands and of insular food during times of drought or fire-induced food shortage. Diminutive size of M. exilis principally reflects lack of island predators, an adaption to periodic food stress in a finite forage area affected by periodic drought and fire, and an adaptation for keeping population numbers high to maintain genetic variability and to ensure survival despite accidents. A late Quaternary scenario describes the environmental setting of the Santa Barbara Channel and the conditions that led to proboscidean dispersal to the preexistent super-island Santarosae.
Thesis (Ph. D.)--University of Colorado at Boulder, 1981. Includes bibliographical references (leaves [237]-258). Typescript photocopy.
"May 1982." Thesis (Ph. D.)--Yale University, 1982. Includes bibliographical references (p. 263-277). Photocopy.
The California Continental Borderland: Landbridges, watergaps, biotic dispersals, and 128,000 years of fluctuating ecospace in an optimal living environment
- Johnson
Johnson, D. L. (1983). The California Continental Borderland: Landbridges, watergaps, biotic disper-sals, and 128,000 years of fluctuating ecospace in an optima1 living environment. In " Quatemary Coast-lines and Marine Archeology " (P.M. Masters and N. C. Flemming, Eds.), pp. 481-527. Academic Press, New York.
Analysis of avifaunal and bat remains from midden sites on San Miguel Island
- Guthrie
Topographic evolution of the Southern California Borderland during Late Cenozoic Time
- Vedder
Early man on Santa Rosa Island
- Berger
Was there a Quaternary land bridge to the Northern Channel Islands?
- Junger
Vegetative Changes and the Impact of Feral Animals
- Power
Ice Age Elephants of the Channel Islands
- Stock
Geology of San Nicholas Island
- Vedder
Elephants of the Santa Barbara Channels Islands, Southern California
- Madden