New records of Michigan Pleistocene vertebrates with comments on the Mason-Quimby line.
Originally published in the Michigan Academician Vol. XXIII, No. 3 (Summer 1991): 273-83
Editor's Comments. Interest concerning the relationships between mastodonts and mammoths and early humans in Michigan was sparked by the provocative papers of two authors, Ronald Mason (1958) and George I. Quimby (1958, 1960). These authors were not only interested in human chronology in the Pleistocene of Michigan, but also by the related question of how these people subsisted in the environment in which they lived. Mason questioned why there were no human fluted spear points in the northern third of the Lower Peninsula and suggested there were ecological reasons for the limited distribution of these artifacts.
Quimby noted relationships between humans, vegetation, arid proboscideans. Both Mason and Quimby believed that the early humans of the entire Great Lakes region The Great Lakes region can refer to:
Although this assumption was questioned by Cleland (1966), the term "Mason-Quimby Line" became a common one to depict the northern extent of all of the valid mastodont and mammoth records in the state as well as most of the Pleistocene human discoveries. (e.g., Holman 2001, Figure 10, 19). In fact, the name became so popular that abbreviated references such as "north or south of the "MQ" are understood by both archaeologists and paleontologists.
The Holman (1991) paper includes a re-examination of the Mason-Quimby Line from the standpoint that there are no authentic Pleistocene records of any mammal species north of the line. It was suggested that a parsimonious par·si·mo·ni·ous
Excessively sparing or frugal.
parsi·mo explanation of this could be based on the end positions of the ice sheet near the termination of the Wisconsinan and the mass of sterile sediments that must have been left in its wake. It was proposed that the area north of the Mason-Quimby line was basically an ecologically unstable tension zone during interstadial and postglacial post·gla·cial
Relating to or occurring during the time following a glacial period.
Relating to or occurring during the time following a glacial period.
Adj. 1. Wisconsinan times, and thus was unable to support sufficient numbers of mammals to contribute to the fossil record. To add to this, there are no authentic Pleistocene records of any vertebrates (fishes, birds, amphibians, reptiles) north of the Mason-Quimby line (Holman 2001).
Relative to the authenticity of Pleistocene vertebrate records in Michigan; most vertebrate paleontologists would want the preserved remains to meet at least one of the following criteria to be considered of Pleistocene age:
A. To represent a known extinct Pleistocene vertebrate.
B. To beat least 10,000 radiocarbon years old.
C. To be in association, in undisturbed context, with an extinct Pleistocene vertebrate.
D. To be found in undisturbed Pleistocene Lake Bed sediments
E. To be found in association, in undisturbed contest, with Pleistocene human artifacts.
The few records of Michigan Pleistocene vertebrates, other than the numerous reported occurrences of proboscideans, is are striking (Holman 1988). Thus, the discovery of an extinct giant beaver (Castoroides ohioensis) jaw, only the tenth record of this species from the state, and north of previous records, is important. Moreover, the discovery of mammoth (Mammuthus sp.) remains (which have since been radiocarbon dated) near the northern limit of its range in Michigan, and in an unusual stratigraphic setting, is also noteworthy. The present paper details these recent finds and provides new comments about the significance of the "Mason-Quimby Line," a line that marks the northern limit of mastodont and mammoth distribution in Michigan, as well as most of the Paleoindian fluted points in the state (Dorr and Eschman 1971).
SYSTEMATIC PALEONTOLOGY paleontology (pā'lēəntŏl`əjē) [Gr.,= study of early beings], science of the life of past geologic periods based on fossil remains.
Castoroides ohioensis Foster, Giant Beaver
Material--Right dentary Den´ta`ry
a. 1. (Anat.) Pertaining to, or bearing, teeth. with two molars and part of the incisor incisor /in·ci·sor/ (I) (-si´zer)
1. adapted for cutting.
2. incisor tooth.
n. present (Figure 1). The specimen is presently owned by the person who found it, Mr. Larry Martinez of Leslie, Michigan.
Locality--The specimen was found on the Lake Michigan beach near Ludington in the SE corner of Sec. 32, R 18 W, T 18 N, Hamlin Township, Mason County, Michigan Hamlin Township is a township in Mason County, Michigan, United States. The population was 3,192 at the 2000 census. Geography
According to the United States Census Bureau, the township has a total area of 89.0 km² (34.4 mi²). 71.2 km² (27.5 mi²) of it is land and 17. , on May 6, 1989, by Vicky Collier and Larry Martinez of Leslie, Michigan.
Remarks--The specimen (Figure 1) is from a very large individual. Measurements are given in Table 1. Two of the original four molars are in place in the jaw, and part of the right incisor is present within its alveolus alveolus (ălvē`ələs): see lungs. . The incisor has the characteristic striations of Castoroides ohioensis.
This record is approximately 30 km north of the previous northern-most record for the species, which is in Midland, Michigan (Wilson 1967), and is approximately 53 km north of the Mason-Quimby Line. There are only nine other records of C. ohioensis in Michigan. There are two records in Berrien County (Hay 1923, and Holman et al. 1986) and one record each for seven other counties: Lenawee, Washtenaw, Ingham, Eaton, Shiawassee, Lapeer, and Midland (Hay 1923; Wilson 1967; Holman et at. 1986).
On June 16, 1989, a trip was made to the Ludington locality by Peter Carrington, J. A. Holman, and Grahame Larson of Michigan State University Michigan State University, at East Lansing; land-grant and state supported; coeducational; chartered 1855. It opened in 1857 as Michigan Agricultural College, the first state agricultural college. . No organic strata were found along the lakeside dunes in the vicinity where the fossil was picked up on the beach, but several large slabs of peat and shelly marl Marl, city, Germany
Marl (märl), city (1994 pop. 92,590), North Rhine–Westphalia, W Germany. It is an industrial and mining (coal, lead, and zinc) center, and also supports a number of chemical factories. were found on the beach nearby. Since Pleistocene fossil vertebrates are often found at peat-marl contact zones in Michigan (Holman 1988), it seems very possible that the giant beaver jaw was derived from the parent layers of these slabs, or perhaps from the slabs themselves. Dr. Larson postulated that these slabs may have eroded from the lake bottom.
Mammuthus sp., Mammoth
Material--Upper third right molar (Figure 2) and a first right rib (Figure 3), Michigan State University Museum Vertebrate Paleontology Collection (MSUVP) Number 1219. The identification of the rib was confirmed, and its position on the skeleton determined, by Daniel Fisher of the University of Michigan (body, education) University of Michigan - A large cosmopolitan university in the Midwest USA. Over 50000 students are enrolled at the University of Michigan's three campuses. The students come from 50 states and over 100 foreign countries. Museum of Paleontology.
Locality--The bones were found during the enlargement of a farm pond near Alger in the SE 1/4, NE 1/4, NW 1/4, Sec. 8, T 20 N, R 3 E, Moffat Township, Arenac County, Michigan Arenac County is a county in the U.S. state of Michigan. As of the 2000 census, the population was 17,269. The county seat is Standish6. Geography
According to the U.S. Census Bureau, the county has a total area of 1,763 km² (681 mi²). , in August, 1988, by Jerry Van Horn of Alger, Michigan.
Carbon 14 Date--The distal portion of the mammoth rib (MSUVP 1219) was submitted for Carbon 14 dating to Beta Analytic, Coral Gables, Florida Often called "The Gables," Coral Gables is a city in Miami-Dade County, Florida, southwest of Miami, in the United States. The city is best known as the home of the University of Miami, and as an example of City Beautiful urban planning. , in July, 1989, and a date was received in August, 1989. This date was based on collagen extracted from the bone. The date was 11,280 [+ or -] 70 B.P. (Beta No. 32130). This date is very consistent with other reliable dates on Michigan mastodonts and mammoths (Agenbroad 1984; Holman et al. 1986).
Metrical Procedures--Metrical data for the Van Horn mammoth tooth was obtained by following as closely as possible the metric techniques described by Maglio (1973). Measurements of enamel thickness are given to the nearest 0.10 mm, other measurements are given to the nearest mm. Abbreviations (given in brackets) are from Maglio.
The total length (L) of the molar, measured perpendicular to the average lamellar lamellar /la·mel·lar/ (lah-mel´ar)
1. pertaining to or resembling lamellae.
2. lamellated (1).
pertaining to or emanating from lamella. plane, is 270 mm. The width (W) at the widest part of the molar is 102 mm. The maximum crown height (H) is 165 mm. The number of plates (x + P) is two or possibly three anterior plates (x) obscured by wear, followed by 27 clearly defined plates (P).
The lamellar frequency (LF) was 9. This number was calculated by counting the number of lamellae lamellae
n the nearly parallel layers of bone tissue found in compact bone. occurring in 100 mm intervals on the basal and apical apical /ap·i·cal/ (ap´i-k'l) pertaining to an apex.
1. Relating to the apex of a pyramidal or pointed structure.
2. parts of both the buccal buc·cal
1. Of, relating to, adjacent to, or in the direction of the cheek.
2. Of or relating to the mouth cavity.
buccal and the lingual sides of the tooth and dividing this number by four (Maglio 1973, 12). An enamel thickness (ET) of 2.0 mm was derived by taking the mean value of measurements of clearly exposed enamel layers from ten lamellae near the middle of the occlusial surface of the tooth. Taxonomic Allocation--The systematics systematics: see classification. of species of Mammuthus is presently unstable. The late Wisconsinan Mammuthus of Michigan have most consistently been called Mammuthus jeffersoni (e.g., Skeels 1962; Wilson 1967; Dorr and Eschman 1971; Holman 1975; and Holman et al. 1986). Other authors (e.g., Agenbroad 1984) have used the name Mammuthus columbi (a name often associated with more southern forms of Mammuthus) for Michigan specimens.
Finally, some early authors (apparently in error, Skeels 1962) attributed Michigan mammoth teeth to Mammuthus primigenius (wooly wool·y
adj. & n.
Variant of woolly.
Adj. 1. wooly - having a fluffy character or appearance
soft - yielding readily to pressure or weight
2. mammoth), a name that is usually applied to more northerly forms that are known to have had long black hair (Anderson 1984).
It is intriguing that in the present specimen the lamellar frequency (LF) of 9 seems in line with the definition of Mammuthus jeffersoni (and perhaps M. columbi), whereas the plate count (x + P) of [+ or -] 3 plus 27 seems in line with the definition of Mammuthus primigenius (20-27 for the upper third molar, Anderson 1984).
Additional Remarks--The Van Horn Site is near the northern extent of records of mammoths in Michigan, being exceeded only by a mammoth find from central Iosco County (Holman 1988, 35, Figure 1). Previous to the present record, 47 records of Mammuthus have been recognized in Michigan (Shoshani 1989).
The stratigraphic setting of the Van Horn mammoth site is unusual for Michigan, as most mammoth and mastodont occurrences have been in ancient bogs that filled kettle-like depressions or shallow basins left by melting glacial ice. The widely accepted hypothesis is that these huge animals wandered out onto unstable mats of vegetation (quaking bogs), fell through the mats, mired and drowned, and then became preserved in the acidic sediments (Holman 1975).
The usual stratigraphic sequence for such sites (from bottom to top) consists of (1) glacial sand and gravel; (2) bluish-gray pure clay derived from the parent glacial material; (3) colloidal colloidal
of the nature of a colloid.
a bath containing gelatin, bran, starch or similar substances, to relieve skin irritation and pruritus. marl with wood, coniferous cones, plant fiber, and freshwater shells; (4) peat; and (5) humus humus (hy`məs), organic matter that has decayed to a relatively stable, amorphous state. It is an important biological constituent of fertile soil. and topsoil. The mammoth and mastodont bones are usually found in the zone between the top of the marl and the bottom of the peat. This indicates the ecological succession of a shallow, well-aerated pond or small lake (zone 3 above) to a "quaking bog" stage (zone 4 above) to a willow-sedge community (modern).
A trip to the Van Horn Site was made by Laura Abraczinskas, J. A. Holman, and Dennis Parmley of Michigan State University on August 18, 1988. Here, as far as we could determine by examining the excavation made to enlarge the pond, the stratigraphic sequence was as follows (from bottom to top): (1) mixed clay and gravel (possibly a disturbance of zones similar to zones 1 and 2 above); (2) about 1.6 m of "beach sand"; (3) about 6.5 m of blackish organic sand (possibly disturbed); and (4) humus and top soil. We could find no evidence of former presence of marl or peat layers; and there were no plant macrofossils or shells (which occur by the countless thousands in usual proboscidean sites) to be found on any of the exposed surfaces of the site or within any matrix examined from the site.
Although neither of the mammoth specimens were found by Mr. Van Morn in situ (as far as we could determine), the Carbon 14-dated rib (Figure 3) had organic material (plant fiber) with some sand grains adhering to concavities in its proximal end. One might make the assumption then, that the bone had been in place near the "beach sand"--blackish organic sand contact.
The Carbon 14 date places the Van Horn mammoth rib near the time it is believed all mammoths became extinct, "about 11,000 years ago" (Anderson 1984). The extinction of mammoths is said to be due to overspecialization, climatic changes, and increasing hunting pressure by humans (Anderson 1984; Kurten and Anderson 1980; Maglio 1973; and Saunders 1980). The Carbon 14 date of ca 11,280 B.P. would also place the Van Horn mammoth only about two or three hundred years after the maximum Greatlakian advance of 11,500 B.P. when Glacial Lake Algonquin Lake Algonquin was a proglacial lake that existed in east-central North America at the time of the last ice age. Parts of the former lake are now Lake Huron, Georgian Bay and inland portions of northern Michigan. slightly overlapped the area (Dorr and Eschman 1971, 157, 173, fig. 13-9). It might be reasoned that two to three hundred years later, at the time of the accumulation of the mammoth bones, the lake had retreated somewhat, and that the bones accumulated near the edge of the lake in beach sand. It finally might be suggested that the bones were then buried under the blackish organic sandy layer as the lake basin filled in.
Occurrences of proboscideans in southern Ontario are known from lake sediments as well as in shallower basins and ponds (McAndrews and Jackson 1988), but this type of occurrence has not often been suggested for Michigan Pleistocene vertebrates. It would be very desirable to have more detailed stratigraphic information about mammoth and mastodont sites in the vicinity of the various glacial lakes of Michigan.
COMMENTS ON THE MASON-QUIMBY LINE
In the process of checking the fossil occurrences of giant beavers and mammoths in Michigan, I have reflected upon the distribution of all of the extinct Pleistocene vertebrates in Michigan and their relationships to the so-called Mason-Quimby Line. The Mason-Quimby Line is presently perceived as a line drawn across the northern extent of all of the valid mastodont and mammoth records in Michigan, as well as most of the Paleoindian discoveries in the state (Holman 1975; Martin 1984; Holman et al. 1986; and Holman 1990). The name acknowledges the provocative writing and maps of R. J. Mason (1958) and G. I. Quimby (1958, 1960).
Mason and Quimby were mainly interested in Paleoindian chronology in Michigan, but they were also interested in the related questions of the subsistence of these people and the paleoenvironment in which they lived. Mason questioned why there were no fluted points north of counties in the southern one-third of the Lower Peninsula and suggested ecological reasons for the limited distribution of these finds. Quimby noted relationships between humans, vegetation, and proboscideans. Both Mason and Quimby believed that Paleoindians of the entire Great Lakes Region hunted mastodonts. This was based on the fact that they believed that many of the fluted points of the region were very similar to the Clovis points in the West used by mammoth hunters.
Later, Quimby (1960) stated that the distribution of fluted points and known mastodont remains in the state was related to the probability that Paleoindians hunted these proboscideans. Although this assumption was seriously questioned by Cleland (1966), the term "Mason-Quimby Line" has been a commonly used term in published writings and in classroom teaching in Michigan for the past two decades. In fact, the term is so common that abbreviated references such as "north or south of the MQ" are understood by most archaeologists and paleontologists.
It occurs to me that one more attribute of the Mason-Quimby Line has never been pointed out in the literature. This is that the Mason-Quimby Line also encompasses all of the previously reported records of extinct Pleistocene vertebrates from Michigan. These animals include (alphabetically): Bootherium bombifrons (woodland musk ox musk ox, hoofed ruminant mammal, Ovibos moschatus, found in arctic North America and Greenland. The northernmost member of the cattle family, the musk ox grazes on the stunted vegetation of the tundra. ), Castoroides ohioensis (giant beaver), Cervalces scotti (woodland caribou), and Platygonus compressus (woodland peccary peccary (pĕk`ərē), small wild pig, genus Tayassu, the only pig native to the Americas. Although similar in appearance to Old World pigs, peccaries are classified in a family of their own because of anatomical differences. ) (e.g., Hay 1923; MacAlpin 1940; Skeels 1962; Wilson 1967; Dorr and Eschman 1971; Holman et al. 1986; Holman 1988, 1990; and Shoshani 1989). Other alleged Pleistocene vertebrates have been recorded from north of the line (e.g., Wilson 1967; Dorr and Eschman 1971), but none of them represent extinct species.
This raises two issues, I believe. One issue is that it appears quite possible that no true Pleistocene vertebrates have ever been recorded from north of the Mason-Quimby Line. The Pleistocene is now considered to have ended about 10,000 years ago by almost all of the scientific community, and I know of no Carbon 14-dated vertebrates that have been recorded from north of the Mason-Quimby Line. In fact, I have long suspected that moose and caribou bones that are assigned to the "Pleistocene age" (e.g., Dorr and Eschman 1971), are actually from much younger deposits. Certainly, the fact that mammals may be buried under several feet of peat and marl does not require that they be Pleistocene. The Harper Site in Shiawassee, Michigan, lies under eight feet of peat, but wood from the marl below the peat has been dated at ca. 5,800 B.P. (Holman et al. 1986).
The other important issue to consider is that whatever physical and biotic biotic /bi·ot·ic/ (bi-ot´ik)
1. pertaining to life or living matter.
2. pertaining to the biota.
1. Relating to life or living organisms. factors restricted the distribution of mastodonts, mammoths, and humans in the late Pleistocene of Michigan also restricted the distribution of all of the extinct Pleistocene vertebrates and, as stated above, possibly most or all of the Pleistocene vertebrate fauna.
The most parsimonious explanation may be derived from a consideration of the known positions of the ice margin in Michigan during the last deglaciation de·gla·ci·a·tion
The uncovering of glaciated land because of melting or sublimation of the glacier.
The uncovering of land that was previously covered by a glacier. episodes. At 14,100 B.P. the end of the ice was about 50km south of the Mason-Quimby Line; and at 12,900 B.P. it was about 100 km north of the line (Mickelson et al. 1983 and Figure 4, this paper). As the ice retreated between these intervals, it must have left a mass of sterile mud and sand in its wake that had to be recolonized by plants and animals. Therefore, the Mason-Quimby Line may represent a tension zone between biotically sterile land to the north and newly re-colonized land to the south.
Figure 4 shows the Mason-Quimby Line as it was last depicted in the literature (Holman 1988; Holman 1990). If the concept of the Mason-Quimby Line is broadened to include all of the extinct Michigan vertebrates as well as mammoths and mastodonts, then the line in Figure 4 should be looped over the new giant beaver record at Ludington!
TABLE 1 Measurements of Ludington, Michigan, Castoroides canadensis Right Dentary Length of tooth row 74mm Greatest length of lower molar II 18 mm Greatest length of lower molar III 16 mm Greatest length of mandibular symphasis 75 mm Greatest length, tip of jaw through condyloid process 202 mm Greatest length of alveolus I 22mm Greatest length of alveolus IV 22 mm Greatest width of alveolus I 26mm Greatest width of alveolus IV 18 mm
I wish to give special thanks to Mr. Jerry Van Horn of Alger, Michigan, for donating the mammoth fossils discovered by him on his property to the Michigan State University Museum. I also wish to thank Mr. Larry Martinez of Leslie, Michigan, for allowing us to photograph and measure the giant beaver jaw that he discovered. Peter Carrington kindly photographed the giant beaver dentary. Laura Abraczinskas helped us verify the exact location of the Van Horn Mammoth Site. Lisa Hallock and Teresa Petersen made the figures. Daniel Fisher and Russell Graham were very helpful critical reviewers of this article, but any errors and omissions errors and omissions n. short-hand for malpractice insurance which gives physicians, attorneys, architects, accountants and other professionals coverage for claims by patients and clients for alleged professional errors and omissions which amount to negligence. are my own.
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