First record of the extinct ground sloth, Megalonyx jeffersonii, (Xenarthra, Megalonychidae) from New York and contributions to its paleoecology

Accepted Manuscript First record of the extinct ground sloth, Megalonyx jeffersonii, (Xenarthra, Megalonychidae) from New York and contributions to its paleoecology H. Gregory McDonald, Robert S. Feranec, Norton Miller PII:

S1040-6182(18)30325-2

DOI:

https://doi.org/10.1016/j.quaint.2018.11.021

Reference:

JQI 7641

To appear in:

Quaternary International

Received Date: 13 March 2018 Revised Date:

19 June 2018

Accepted Date: 15 November 2018

Please cite this article as: McDonald, H.G., Feranec, R.S., Miller, N., First record of the extinct ground sloth, Megalonyx jeffersonii, (Xenarthra, Megalonychidae) from New York and contributions to its paleoecology, Quaternary International (2018), doi: https://doi.org/10.1016/j.quaint.2018.11.021. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

ACCEPTED MANUSCRIPT

H. Gregory McDonald Bureau of Land Management Utah State Office 440 West 200 South Salt Lake City, Utah 84101-1345

SC

Robert S. Feranec New York State Museum 3140 Cultural Education Center Albany, New York 12230

RI PT

First Record of the extinct Ground Sloth, Megalonyx jeffersonii, (Xenarthra, Megalonychidae) from New York and contributions to its paleoecology

M AN U

Norton Miller † Biological Survey New York State Museum 3140 Cultural Education Center Albany, New York 12230 † Deceased Abstract

TE D

The first record of the Jefferson ground sloth, Megalonyx jeffersonii, in New York is reported. The specimen consists of a partial synsacrum recovered from a peat deposit near Newburgh, Orange County. Compared to other synsacra of Megalonyx, the number

EP

of vertebrae is anomalous with one less caudal vertebra than expected. Stable isotope analysis of the bone shows a δ13C value of 20.5‰ and implies a diet of only C3 plants.

AC C

The specimen has a radiocarbon date of 11,450 ± 55 BP indicating the presence of this taxon in the region immediately prior to the extinction of the North American Pleistocene megafauna.

Keywords Megalonyx jeffersonii, synsacrum, New York, stable isotopes

1

ACCEPTED MANUSCRIPT

1. Introduction While the Pleistocene fauna of New York is diverse (Hartnagel and Bishop, 1922; Funk and Steadman, 1994; Laub, 2003) including such taxa as mammoth, mastodon,

RI PT

giant beaver and peccary, representatives of one common group present in the North

America Pleistocene fauna, the ground sloths, have not yet been reported from the state. The North American late Pleistocene fauna included four ground sloth taxa;

SC

Eremotherium laurillardi, Nothrotheriops shastensis, Megalonyx jeffersonii, and

Paramylodon harlani. The first two species are confined to the southeastern and

M AN U

southwestern parts of the United States respectively, while the distribution of each of the second two taxa is sufficiently widespread in North America that either might be expected to have been present in New York in the late Pleistocene. We report here the first record of Jefferson’s ground sloth, Megalonyx jeffersonii, from the Hudson River

TE D

Valley of New York, and an interpretation of its ecology based on stable isotope analysis. 2. Description of Locality and Geology The specimen recovered, a synsacrum, one of the diagnostic features of the

EP

Xenarthra (McDonald, 2003), was found during construction of I-84 (originally Interstate 503) north of Newburgh, Orange County, New York between highway 9W and the

AC C

Thruway (Fig. 1). The site is referred to as the Newburgh Sloth Location: N 41° 31' 07.74", W° 74 01" 58.63”, elevation 78 m. (Fig. 1). It was collected September 24, 1962 by Gerald Illenbergh of Middletown, New York and donated to the New York State Museum. 3. Age of Specimen A radiocarbon date of 11,450 ± 55 BP (NOSAMS OS-64987; 13,160-13,420 cal BP) was obtained for this specimen (Table 1). This date was obtained from bone collagen

2

ACCEPTED MANUSCRIPT

using standard A-B-A pretreatment with ultrafiltration using the protocol described in Feranec and Kozlowski (2016). The sample was graphitized and analyzed at the National

4. Description of the Newburgh Specimen

RI PT

Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) facility (Woods Hole, MA).

The specimen (NYSM VP-46), a partial synsacrum, is incomplete, lacking most of the left ilium, the lateral margin of the right ilium, the left ischium and most of both

SC

pubes (Fig. 2). The acetabulum is incomplete with only the posterior margin including the posterior notch of the acetabular fossa preserved. The sacral and caudal vertebral

M AN U

series is complete and is composed of four vertebrae, three sacral and one caudal. The specimen is from an adult and all bones are fused with no visible sutures. The anterior portion of the first sacral vertebrae has only one extra pair of articular surfaces (the xenarthrous condition). These extra articular surfaces (the fused anterior lateral

TE D

zygapophyseal facet and anterior xenarthrous facet of Gaudin (1999) are positioned ventrally and slightly laterally to the prezygopophyses and consist of a single flat oval surface that faces dorsally. The mammilla-articular processes are distinct. The median

EP

sacral crest is mediolaterally widest at its anterior margin and narrows posteriorly. The first dorsal sacral foramen opens into the neural canal while the second and third open

AC C

directly ventrally just above their complementary pelvic sacral foramen. The three pelvic sacral foramina are large and the middle one is the largest of the three. The opening of the most anterior sacral pelvic foramen faces ventrally while the middle and last ones have a more laterally facing opening. There are few relatively complete synsacra of Megalonyx (Table 2) reported in the literature and consequently it has never been adequately described. Harlan (1835)

3

ACCEPTED MANUSCRIPT

discussed and figured a specimen from Big Bone Cave, Tennessee as the acetabulum and partial right ilium but the specimen is a right calcaneum (ANSP 12492). Leidy (1855) described a number of sacral fragments (ANSP 15572) from Natchez, Mississippi and

RI PT

Safford (1892) described a nearly complete juvenile pelvis from Big Bone Cave (ANSP 15193). Stovall (1940) mentioned a pelvis (OMNH 4326, originally reported as 41-0-S1) associated with the type specimen of Megalonyx hogani (= Megalonyx jeffersonii) but did

SC

not describe the specimen. A complete pelvis was part of the partial skeleton of

Megalonyx jeffersonii recovered from the SeaTac Airport, Washington (UW 20788)

M AN U

(McDonald, 1998). The Newburgh specimen is the second most complete synsacrum of an adult Megalonyx after the Washington specimen.

Except for the mylodont sloths, there are usually five vertebrae incorporated into the synsacrum of sloths, three sacral and two caudal. The Santacrucian (Miocene) genus

TE D

Hapalops has the pattern of five vertebrae incorporated into the synsacrum and follows the pattern of the first three articulating with the ilium, the fourth having no articulation with the pelvis and the fifth articulating with the ischium (Scott, 1903). This pattern has

EP

been observed in Megatherium (Owen, 1855) and Nothrotheriops (Stock, 1925) as well as the modern genus Bradypus. The other living genus of sloth, Choloepus, has seven

AC C

vertebrae (Owen, 1855). Based on the Washington and Oklahoma (type of Megalonyx hogani) synsacra the pattern of three sacral and two caudal vertebrae is also characteristic of Megalonyx. As described above, the Newburgh specimen is unusual in that only three sacral and one caudal vertebra are present in the synsacrum. In the Washington specimen all three sacral vertebrae articulate with the ilium, and only the second caudal contacts the ischium and the transverse process of the first caudal connects the transverse processes of

4

ACCEPTED MANUSCRIPT

the last sacral and second caudal but does not contact the pelvis. Although the Oklahoma specimen has five vertebrae they are separated from the ilia so it is not possible to accurately determine their contacts with the pelvis, but based on the preserved portions

RI PT

the pattern seems to be the same as the Washington specimen. In the Newburgh

specimen the transverse processes of the first two sacral vertebrae contact the ilium but

the transverse process of the third sacral does not. The anterior and posterior margins of

SC

the transverse process of the third sacral is expanded to contact the transverse process of

first caudal contacts the ischium.

M AN U

the second sacral and the first caudal to form a bridge. Only the transverse process of the

Asher et al. (2011) noted that within placentals the Xenarthra, Afrotheria and Primates showed relatively high variation in the thoracolumbar vertebral count and the corrected coefficient of variation for the Xenarthra was the highest of all the groups

TE D

examined with a value of 3.340. The high CV was usually due to meristic variations from either the presence of extra vertebrae or a reduction in number. Unfortunately, they did not examine the sacrum in their analysis but the absence of a vertebrae in the

EP

Newburgh specimen compared to other Megalonyx synsacra suggests the degree of variation observed in the thoracic and lumbar vertebra in Xenarthra, including the living

AC C

sloths, Bradypus variegatus and Choloepus hoffmanni, also extends into the sacrum as well. Galis and Metz (2007) proposed that this deviation was possible due to the lower metabolic rate in these animals. In all specimens the neural spines of the sacral and caudal vertebrae in the

synsacrum are coalesced into a single continuous neural crest. The neural crest height decreases posteriorly. Each of the adjacent fused transverse processes is perforated by a

5

ACCEPTED MANUSCRIPT

single foramen positioned lateral to the mammalliary process. Each foramen in the transverse process is positioned immediately dorsal to the foramen formed between the adjacent sacral vertebrae. Although all of the vertebrae are co-ossified the contact

RI PT

between each vertebra is visible as a transverse line just posterior to the mammalliary

processes. The width is greater then the height of the anterior centrum of the synsacrum and the centra becomes increasing flattened posteriorly.

SC

As in other sloths, the ilia are expanded laterally so that the origins of the gluteal muscles are on the dorsal surface. The dorsal surface is flat with rugose anterior and

M AN U

lateral margins. There are five muscle scars marking the origin of the superficial and medial gluteal muscles. They are arranged in a radiating pattern that originates from in front of the acetabulum and diverge towards the medial and anterior edges of the ilium. Just anterior to the acetabulum and extending mediolaterally is a small series of ridges

TE D

marking the origin of the deep gluteal muscle. The ventral surface of the ilium is concave and has only two muscle scars that radiate from in front of the acetabulum. The acetabular portion of the pubis is a short rectangular bar that extends

EP

posteromedially and ventrally. The pubic symphysis is short but thick at its midline and thins laterally. The ventral surface of the symphysis is rounded and rugose.

AC C

The center of the acetabulum lies in the posterior third of the pelvis. It faces

posterolaterally from the sagittal plane at about a 40° angle. It lacks the ventral depression present in both Paramylodon and Nothrotheriops. In these other two genera the dorsal margin of the acetabulum extends over the head of the femur so that the pelvis rests on top of the femur indicating a more graviportal structure. In Megalonyx there is no dorsal extension of the acetabulum and the articulation of the femur is more laterally

6

ACCEPTED MANUSCRIPT

placed so is similar to that of giant anteaters and non-graviportal forms. The articular surface of the acetabulum is partially divided by a vertical acetabular fossa. The anterior half of the articular surface formed by the ilium is nearly hemispherical and the ischium

RI PT

and pubis equally contribute to the posterior portion. In the Newburgh specimen the

posterior portion of the right acetabulum is the only portion preserved and it contains a well-developed acetabular notch. In the Washington specimen the right side has the

SC

notch which separates the ischium and pubis but on the left side the edges of the notch

have grown over to form a foramen. There is a well-developed ilio-pectineal eminence

M AN U

that extends medially from the inner surface of the acetabulum. A slight pubic tubercle is present and located just posterior to the ilio-pectineal eminence.

The transverse processes of the most posterior caudal vertebra in the synsacrum contacts the ischium in both the New York and Washington specimens. The posterior

triangular in shape.

TE D

margin of the ischium is enlarged and forms a prominent ischial tuberosity that is

In the juvenile specimen from Big Bone Cave all three centers of ossification of

EP

the pelvic portion of the synsacrum are well formed but only the suture between the ischium and pubis is fully ossified, all other sutures in the specimen have remained

AC C

connected by the presence of the dried cartilage or they would have otherwise separated. The ilia in the Tennessee specimen are not yet fused to the pubis or ischium. The posterior surface of the first sacral vertebrae and anterior part of the centrum of the second sacral vertebra retains distinct epiphyseal plates which are connected by dried cartilaginous intervertebral discs. The contact between the centra of the first and second sacral vertebrae in the Newburgh specimen is still visible on their ventral surface,

7

ACCEPTED MANUSCRIPT

although the animal is an adult. In all the other vertebrae of the Tennessee specimen the intervertebral discs between the centra of the vertebrae have been lost and the posterior and anterior epiphyseal plates have coalesced. In the Newburgh specimen this is also the

RI PT

case and although it is of an older individual so while the contact between the centra of the first and second sacral vertebrae can be seen on the ventral surface it is not visible

between the other vertebrae. Although most of the neural spines in the Big Bone Cave

SC

specimen are missing, enough is preserved to indicate that the neural spines of the first

5. Stable Isotope Analysis

M AN U

two sacral vertebrae had already fused, even though it is a juvenile animal.

Examination of stable isotope values within ancient mammal tissues has proven useful for identifying dietary and habitat preferences. Here we examine the carbon and

TE D

nitrogen isotope data from bone collagen of this specimen. Isotopic results are expressed in the standard δ-notation: X = [(Rsample/Rstandard) - 1] × 1000, where X is the δ13C or δ15N value, and R = 13C/12C or 15N/14N, respectively. The δ13C values are reported relative to

EP

the V-PDB standard, while δ15N values are reported relative to atmospheric N2. For mammals, carbon isotope values generally reflect differences in the

AC C

percentages of C3 plants and C4 plants consumed (Koch, 1998; Deniro and Epstein, 1978a,b). Taking into account the isotopic values displayed by the different photosynthetic pathways, the fractionation of isotopic values from plant material to collagen, and the changes in δ13C values of atmospheric CO2 since the Pleistocene (Ambrose and DeNiro, 1986; Ehleringer and Monson, 1993; Ehleringer et al., 1991; Farquhar et al., 1989; Friedli et al., 1986; Marino and McElroy, 1991; Marino et al.,

8

ACCEPTED MANUSCRIPT

1992; O’Leary, 1988; Sealy et al., 1987), a diet of pure C3 plants in Pleistocene mammals would range from –29‰ to –15‰ in bone collagen, while a diet of pure C4 plants would range from –13‰ to –4‰.

RI PT

Nitrogen isotope values in mammals reflect the isotopic composition in the soil on which the plants they fed grew, the composition in their diet, the metabolism of the

particular individual, and trophic level. In areas that are warm and dry, δ15N values in

SC

soils will tend to be more positive (Ambrose and DeNiro, 1986, 1987; Ambrose, 1991; Amundson et al., 2003). δ15N of collagen appears to increase with decreasing

M AN U

precipitation (Heaton et al., 1986; Gröcke et al., 1997; Koch, 1998; Schwarcz et al., 1999; Robinson, 2001). Plants that fix N2 have different isotopic values from plants that do not fix N2. Animals foraging N2-fixing plants tend to have more negative δ15N values compared to animals feeding on plants that do not fix N2 (Ambrose, 1991; Koch, 1998).

TE D

Metabolically, differences in nitrogen isotope values appear to result from drought tolerance or intolerance. Drought tolerant taxa concentrate waste, which results in increased δ15N values in tissue; drought intolerant taxa will have lower isotopic values

EP

(Ambrose, 1991; Koch, 1998; Palmqvist et al., 2003).

AC C

Finally, there appears to be a +3-5‰ shift in δ15N values with each rise in trophic level (DeNiro and Epstein, 1981; Minagawa and Wada, 1984; France et al., 2007; FoxDobbs et al., 2008). Based on our current understanding of the late Pleistocene flora of New York State (Maenza-Gmelch 1997; Dyke 2005) as well as ecological information on M. jeffersonii from previous studies (France et al., 2007; Bocherens et al., 1994). This M. jeffersonii specimen exhibits δ13C values in the C3 range and δ15N values similar to other herbivores as it is suspected to have been a forest dwelling browser. 9

ACCEPTED MANUSCRIPT

To obtain δ13C and δ15N values from collagen, the general methodology of Sealy et al. (1987) was used. Pieces of bone were first placed into 0.5 N hydrochloric acid at room temperature for four days to remove the mineral portion of the bone. Samples were

RI PT

rinsed with distilled water and then decanted once the mineral portion of the bone was fully dissolved. Once decalcified, the collagen was gelatinized at 58 °C for 16 hours.

The gelatin solution was then filtered to remove any remaining solids. The solution was

SC

then ultra-filtered to remove the 30 kD fraction, and the 30 kD fraction was lyophilized. The samples were then analyzed using a Carlo Erba elemental analyzer attached to a

M AN U

Micromass Europa Mass Spectrometer at the Center for Stable Isotope Biogeochemistry at the University of California, Berkeley.

Stable isotope data for sloths is limited but the available data does indicate differences between taxa reflecting differences in their ecology (Haupt et al., 2016).

TE D

Kohn et al. (2005) included Megalonyx in their analysis of the middle Irvingtonian Camelot fauna in South Carolina. The Camelot fauna is considered to be interglacial and most likely correlates with isotope stage 11 (ca 400 ka in age). The stable isotope

EP

analysis of the orthodentine of the sloth tooth gave a range of δ13C of –13.13‰ to – 13.30‰ with a mean of –13.22‰ + 0.07‰ and a range of δ18O of 27.19‰ to 27.59‰

AC C

with a mean of 27.4‰ + 0.18‰ based on 7 samples. The samples were taken along the length of the tooth and the variation in values was attributed to seasonality. The low values for both carbon and oxygen in Megalonyx from the Camelot Site are consistent with previous interpretations of the paleoecology of this genus as a forest dweller and a browser. Since teeth are not available for the Newburgh specimen the stable isotope analysis is not based on orthodentine but on bone collagen.

10

ACCEPTED MANUSCRIPT

To test for diagenesis and the reliability of the obtained isotopic values, we analyzed the bone collagen C/N ratio and the percent yields of both carbon and nitrogen. The C/N ratio (3.43) and the percent yields of both carbon (32.6%) and nitrogen (11.0%)

RI PT

supports the reliability of the observed δ13C and δ15N values from bone collagen in this individual (DeNiro, 1985; Ambrose, 1990; Bocherens et al., 1996; Bocherens et al.,

1997). The δ13C value for this specimen was -20.5‰, and, as predicted, implies a diet of

SC

only C3 plants. The δ15N value was 5.0‰ and is similar to other modern herbivores of

M AN U

NY State (R. Feranec, unpublished data). These isotopic values are also similar to values previously obtained on this species (France et al., 2007) from the late Pleistocene Saltville locality, VA, and suggest that this individual was ecologically typical and supports the idea that this species was a forest-dwelling browser. 6. Discussion

TE D

Since its initial discovery from a cave in West Virginia, Megalonyx jeffersonii has been recorded from multiple sites across North America from coast to coast and from the Yukon south into Mexico. Yet despite its widespread distribution which includes a large

EP

number of late Pleistocene localities (Hoganson and McDonald, 2007 Fig. 3) this is the first record of the species in New York and marks the northeastern most record of the

AC C

species. The next closest localities are in Pennsylvania and New Jersey, each with a single record. It is remarkable that remains of this animal have not been previously found in New York, given the large number of mastodons, a species utilizing the same type of habitat as the sloth, that have been recovered from the Hudson Valley since the 1700’s (Allmon et al., 2008).

11

ACCEPTED MANUSCRIPT

During the last glacial maximum all of New York except for the Salamanca Reentrant in the southwestern part of the state, and the southern-most part of Long Island was covered by the Laurentide Ice Sheet (Feraec and Kozlowski, 2016). Dyke (2005)

RI PT

identified five basic biomes in the late Pleistocene of New York which with the recession of the Laurentide Ice Sheet shifted northward. The rate at which this northward shift of these biomes occurred also determined the rate at which the megafauna moved into the

SC

area. While the Megalonyx is a single data point, its preference for a habitat similar to

the American mastodon, Mammut americanum, which is common in the Hudson River

M AN U

Valley (Thompson et al, 2008) provides a framework to evaluate the sloth’s presence in New York. Feranec and Kozlowski (2016) calculated the earliest appearance of the American mastodon in New York following deglaciation as between 14,540 – 14,090 cal BP (95% HPD) or 14,350 – 14,140 (68% HPD) cal BP based on 21 radiocarbon dates.

TE D

While the mastodon’s first appearance in the state is older than the 13,160-13,420 cal BP for the Megalonyx at both time intervals the area around the Hudson River Valley would have been a boreal forest dominated by spruce (Feranec and Kozlowski, 2016 Fig 1).

EP

Given the widespread distribution of the boreal forest biome in New York between ca. 14,000 and 11,500 yr cal BP one would expect that the sloth, like the

AC C

mastodon with which it shared this biome, would be equally as common. Yet, this is clearly not the case. This may reflect differences in the ecology of the two species and that while they both are associated with a boreal forest biome in the broad sense, within this biome the sloth probably utilized or preferred a smaller ecological subset. While the stable isotope data indicates that the Newburgh sloth was ecologically similar to other Megalonyx and supports the idea that this species was a forest-dwelling browser, it does

12

ACCEPTED MANUSCRIPT

not provide the level of information needed with regard to more specific habitat preferences. The radiocarbon date of 11,450 ± 55 BP for the Newburgh Megalonyx is close in

RI PT

age to that of the Lang Farm Illinois Megalonyx which was dated at 11,430 ± 60 and

11,485 ± 40 14C BP (Schubert et al., 2004). The pollen data from the northern Illinois

locality indicates the sloth lived in a nonanalog environment that was transitional from

SC

midlatitude tundra to a mixed conifer and deciduous woodland, although spruce (Picea sp.) was dominant. It may be that as in Illinois the New York Megalonyx was also

M AN U

utilizing a similar nonanalog environment that had a limited spatial distribution. The Hudson River Valley with associated riverine gallery forest may have been such a habitat. Hoganson and McDonald (2007) noted the close association of Megalonyx with riverine systems on the Great Plains. The location of the Newburgh Megalonyx near the

TE D

Hudson River follows this pattern. 7. Acknowledgements

It is a pleasure to include this contribution to a volume recognizing Holmes

EP

Semken’s many contributions to our knowledge of the North American Pleistocene and Holocene mammalian faunas, particularly with his leadership in the last few years on the

AC C

Tarkio Valley Sloth Project. We thank Gerald Illenbergh for the donation of the sloth specimen to the New York State Museum. Nick Czaplewski, Sam Noble Museum, University of Oklahoma, kindly provided information and help with the type specimen of Megalonyx hogani. We thank the two reviewers for their comments which improved the final manuscript. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

13

ACCEPTED MANUSCRIPT

References Allmon, W.D., Nester, P.L., Clement, J.J., 2008. Introduction: New York State as a locus classicus for the American mastodon. In: Allmon, W.D., Nester, P.L.

RI PT

(Eds.), Mastodon Paleobiology, Taphonomy, and Paleoenvironment in the late

Pleistocene of New York State: Studies on the Hyde Park, Chemung, and North Java Sites. Palaeontographica Americana 61, pp. 5-12.

SC

Ambrose, S.H., 1990. Preparation and characterization of bone and tooth collagen for isotopic analysis. Journal of Archaeological Science 17, 431–451.

M AN U

Ambrose, S.H., 1991. Effects of diet, climate and physiology of nitrogen isotope abundances in terrestrial foodwebs. Journal of Archaeological Science 18, 293317.

Ambrose, S.H., DeNiro., M.J., 1986. The isotopic ecology of East African mammals.

TE D

Oecologia 69, 395-406.

Ambrose, S.H., DeNiro, M.J., 1987. Bone nitrogen isotope composition and climate. Nature 325, 201.

EP

Amundson, R., Austin, A.T., Schuur, E.A.G., Yoo, K., Matzek, V., Kendall, C., A. Uebersax, A., Brenner, D., Baisden, W.T., 2003. Global patterns of the isotopic

AC C

composition of soil and plant nitrogen. Global Biogeochemical Cycles 17, 31.01-31.10.

Asher, R.J., Lin, K.H., Kardjilov, N., Huatier, L., 2011. Variability and constraint in the mammalian vertebral column. Journal of Evolutionary Biology 24, 10801090.

14

ACCEPTED MANUSCRIPT

Bocherens, H., Fizet, M., Mariotti, A., Gangloff, R.A., Burns, J.A., 1994. Contribution of isotopic biogeochemistry (13C, 15N, 18O) to the paleoecology of mammoths (Mammuthus primigenius). Historical Biology 7, 187–202.

RI PT

Bocherens, H.M., Pacaud, G., Lazarev, P.A., Mariotti, A., 1996. Stable isotope

abundances (13C, 15N) in collagen and soft tissues from Pleistocene mammals from Yakutia: implications for the palaeobiology of the Mammoth Steppe.

SC

Palaeogeography, Palaeoclimatology, Palaeoecology 126, 31–44.

Bocherens, H., Billiou, D., Patou-Mathis, M., Bonjean, D., Otte, M., Mariotti, A., 1997.

M AN U

Paleobiological implications of the isotopic signatures (13C, 15N) of fossil mammal collagen in Scladina Cave (Sclayn, Belgium). Quaternary Research 48, 370–380.

DeNiro, M.J., Epstein, S., 1978a, Carbon isotopic evidence for different feeding

TE D

patterns in two hyrax species occupying the same habitat. Science 201, 906-908. DeNiro, M.J., Epstein, S., 1978b. Influence of diet on the distribution of carbon isotopes in animals. Geochimica et Cosmochimica Acta 42, 495-506.

EP

DeNiro, M.J., Epstein, S., 1981. Influence of diet on the distribution of nitrogen isotopes in animals. Geochimica et Cosmochimica Acta 45, 341–351.

AC C

Dyke, A.S., 2005. Late Quaternary vegetation of northern North America based on pollen, macrobotanical, and faunal remains. Géographie Physique et Quaternaire 59, 211-262.

Ehleringer, J.R., Monson, R.K., 1993. Evolutionary and ecological aspects of photosynthetic pathway variation. Annual Review of Ecology and Systematics 24, 411-439.

15

ACCEPTED MANUSCRIPT

Ehleringer, J.R., Sage, R.F., Flanagan, L.B., Pearcy, R.W., 1991. Climate change and the evolution of C4 photosynthesis. Trends in Ecology and Evolution 6, 95-99. Farquhar, G.D., Ehleringer, J.R., Hubick, K.T., 1989. Carbon isotope discrimination

RI PT

and photosynthesis. Annual Review of Plant Physiology and Plant Molecular Biology 40, 503-537.

Feranec, R.S., Kozlowski, A.L., 2016. Implications of a Bayesian radiocarbon

SC

calibration of colonization ages for mammalian megafauna in glaciated New York State after the Last Glacial Maximum. Quaternary Research 85, 262-270.

M AN U

Fox-Dobbs, K., Bump, J.K., Peterson, R.O., Fox, D.L., Koch, P.L., 2007. Carnivorespecific stable isotope variables and variation in the foraging ecology of modern and ancient wolf populations: case studies from Isle Royale, Minnesota, and La Brea. Canadian Journal of Zoology 85, 458-471.

TE D

France, C.A.M., Zelanko, P.M., Kaufman, A.J., Holtz, T.R., 2007. Carbon and nitrogen isotopic analysis of Pleistocene mammals from the Saltville Quarry (Virginia, USA): implications for trophic relationships. Palaeogeography,

EP

Palaeoclimatology, Palaeoecology 249, 271–282. Funk, R.E., Steadman, D.W., 1994. Archaeological and paleoenvironmental

AC C

investigations in the Dutchess Quarry Caves, Orange County, New York.

Persimmon Press Monographs in Archaeology. Buffalo New York.

Galis, F., Metz, J.A., 2007. Evolutionary novelties: the making and breaking of pleiotropic constraints. Integrative and Comparative Biology 47, 409-419.

Gaudin, T.J., 1999. The morphology of xenarthrous vertebrae (Mammalia, Xenarthra). Fieldiana, Geology, n.s. No. 41, 1-38.

16

ACCEPTED MANUSCRIPT

Goffart, M., 1971. Function and Form in the Sloth. Pergamon Press, Oxford. Gröcke, D.R., Bocherens, H., Mariotti, A., 1997. Annual rainfall and nitrogen-isotope correlation in macropod collagen: application as a palaeoprecipitation

RI PT

indicator. Earth and Planetary Science Letters 153, 279-285.

Harlan, R. 1831. Description of the fossil bones of the Megalonyx discovered in “White Cave” Kentucky. Journal of the Academy of Natural Sciences, of Philadelphia

SC

ser. 1, 6, 269-288.

Harlan, R. 1835. Os ilium of the Megalonyx from Big-Bone-Cave, White County,

M AN U

Tennessee. Medical and Physical Researches:336.

Hartnagel, C.A., Bishop, S.C., 1922. The mastodons, mammoths and other Pleistocene mammals of New York State. New York State Museum Bulletin 242, 6-110.

TE D

Haupt, R.J., McDonald, H.G., Clementz, M., 2016. Dietary preferences of the Shasta, ground sloth (Nothrotheriops shastensis) inferred from stable isotope analysis of coprolites. Society of Vertebrate Paleontology Annual Meeting, October 2016

EP

Program and Abstracts, 150.

Heaton, T.H.E., Vogel, J.C., von la Chevallerie, G., Collett,G., 1986. Climatic

AC C

influence on the isotopic composition of bone nitrogen. Nature 322, 822-823.

Hoganson, J.W., McDonald, H.G., 2007. The first report of the occurrence of Jefferson’s ground sloth (Megalonyx jeffersonii) in North Dakota and its paleobiogeographical and paleoecological significance. Journal of Mammalogy 88, 73-80.

17

ACCEPTED MANUSCRIPT

Koch, P.L., 1998. Isotopic reconstruction of past continental environments. Annual Review of Earth and Planetary Science 26, 573-613. Kohn M.J., McKay, M.P., Knight, J.L., 2005. Dining in the Pleistocene – Who’s on

RI PT

the menu? Geology 33, 649-652.

Laub, R.S., 2003. The Pleistocene fauna of the Hiscock Site. In: Laub, R.S. (Ed.), The Hiscock Site: late Pleistocene and Holocene paleoecology and archeology of

SC

Western New York State. Bulletin of the Buffalo Society of Natural Sciences 37, pp. 69-82.

M AN U

Leidy, J., 1855. A memoir on the extinct sloth tribe of North America. Smithsonian Contributions to Knowledge 7, 1-68.

Maenza-Gmelch, T.E., 1997. Late-glacial – early Holocene vegetation, climate, and fire at Sutherland Pond, Hudson Highlands, southeastern New York, U.S.A. Canadian

TE D

Journal of Botany 75, 431–439. doi:10.1139/b97-045

McDonald, H.G., 1998. The Sloth, the President, and the Airport. Washington Geology 26, 40-42.

EP

McDonald, H.G., 2003. Xenarthran skeletal anatomy: primitive or derived? In: Fariña, R.A., Vizcaíno, S.F., Storch, G. (Eds), Morphological studies in fossil and extant

AC C

Xenarthra (Mammalia). Senckenbergiana biologica 83, pp. 1-13.

Minagawa, M., Wada, E., 1984. Stepwise enrichment of 15N along food chains: further evidence and the relation between δ15N and animal age. Geochimica et Cosmochimica Acta 48, 1135–1140.

O'Leary, M.H., 1988. Carbon isotopes in photosynthesis. BioScience 38, 328-336.

18

ACCEPTED MANUSCRIPT

Owen, R. 1855. On the Megatherium (Megatherium americanum, Cuvier and Blumenbach). Part II. Vertebrae of the trunk. Philosophical Transactions of the Royal Society of London 145, 359-388.

RI PT

Palmqvist, P., Gröcke, D.R., Arribas, A., Fariña,R.A., 2003. Paleoecological

reconstruction of a lower Pleistocene large mammal community using

biogeochemical (δ13C, δ15N, δ18O, Sr:Zn) and ecomorphological approaches.

SC

Paleobiology 29, 205-229.

Redmond, B.G., McDonald, H.G., Greenfield, H.J., Burt, M.L., 2012. New evidence

M AN U

for Late Pleistocene human exploitation of Jefferson’s Ground Sloth (Megalonyx jeffersonii) from northern Ohio, USA. In: Outram, A.K., Eren M.I. (Eds.), Faunal Extinctions and Introductions, World Archaeology 44, pp. 75-101. Robinson, D., 2001. δ15N as an integrator of the nitrogen cycle. Trends in Ecology and

TE D

Evolution 16, 153-162.

Safford, J.M. 1892. The pelvis of Megalonyx and other bones from Big Bone Cave, Tennessee. Bulletin of the Geological Society of America 3, 121-123.

EP

Schubert, B.W., Graham, R.W., McDonald, H.G., Grimm, E.C., Stafford Jr., T.W., 2004. Latest Pleistocene paleoecology of Megalonyx jeffersonii and Cervalces

AC C

scotti. Quaternary Research 61, 231-240.

Schwarcz, H. P., Dupras, T. L., Fairgrieve, S.I., 1999. 15N enrichment in the Sahara: in search of a global relationship. Journal of Archaeological Science 26, 629-636.

Scott, W.B. 1903. Mammalia of the Santa Cruz Beds Part I Edentata II Glyptodontia and Gravigrada. Report of Princeton University Expedition to Patagonia, 18961899.

19

ACCEPTED MANUSCRIPT

Sealy, J. C., van der Merwe, N.A., Lee-Thorp, J.A.,Lanham, J.L., 1987. Nitrogen isotopic ecology in southern Africa: Implications for environmental and dietary tracing. Geochimica et Cosmochimica Acta 51:2707-2717.

RI PT

Stock, C., 1925. Cenozoic gravigrade edentates of western North America with special reference to the Pleistocene Megalonychinae and Mylodontidae of Rancho La Brea. Carnegie Institute of Washington 331, 1-206.

SC

Stovall, J.W., 1940. Megalonyx hogani, a new species of ground sloth from Gould, Oklahoma. American Journal of Science 238, 140-146.

M AN U

Stuiver, M, Reimer, P.J., Reimer, R.W., 2005. CALIB 7.1. URL:http://calib.qub.ac.uk/calib/.

Thompson, L.M., MacIntosh, G.C., Allmon, W.D., 2008. Discoveries of the American mastodon (Mammut americanum) in New York State: 1922-2007.

TE D

Paleontographica Americana 61, 25-41.

Fig. 1. Map of location for NYSM VP-46 (Megalonyx jeffersonii) specimen (star) in Orange County, NY.

AC C

EP

Fig. 2. Megalonyx jeffersonii synsacrum (NYSM VP-46) in A. dorsal view, B. ventral view, C. anterior view, D. posterior view, E. left lateral view, F. right lateral view. Scale bar represents 10 cm.

20

ACCEPTED MANUSCRIPT

Table 1. Radiocarbon date from Megalonyx jeffersonii (NYSM VP-46). Calibration data from Reimer et al. (2004). Abbreviations: NOSAMS, National Oceanic Sciences Accelerator Mass

OS-64987

Sample

07 RSF C14-002

NYSM #

VP-46

Element

pelvis

δ13C

-20.47

Fraction Modern

0.2406 ± 0.0042

14C age

11450 ± 55

2σ cal age range (cal BP) rounded to the nearest decade from Stuiver et al. (2005).

TE D

1

M AN U

Species Identification Megalonyx jeffersonii

SC

NOSAMS #

RI PT

Spectrometry facility; NYSM, New York State Museum; comb., combusted; frag. fragment.

Table 2. Pelvic measurements of Megalonyx jeffersonii. Measurements in mm.

EP

Measurement

AC C

Greatest Width Across Ilia Length of centra of fused sacral vertebrae Transverse diameter of anterior face of centrum of first sacral vertebrae Dorso-ventral diameter of anterior face of centrum of first sacral vertebrae Height of first sacral vertebrae base of centrum to dorsal margin of neural process Transverse internal diameter of neural canal of first sacral vertebrae Transverse diameter of centrum of last vertebrae in synsacrum Dorso-ventral diameter of centrum of

New York NYSM VP 46 – 243

Washington UW 20788 1114 329

Tennessee ANSP 15193 930* 284*

111

96

103.5

70

67

59.2

163

216

–

67

70

73.9

73

93

92.3

41

50

32.8

ACCEPTED MANUSCRIPT

330

–

24

28

–

89

110

–

97

126

52

83

–

497

RI PT

246

AC C

EP

TE D

103* __

366.9

SC

M AN U

last vertebrae in synsacrum Length of crest formed by fused neural spines Greatest width of dorsal crest at anterior Height of last vertebrae from base of centrum to dorsal surface of neural spine Width across anterior zygopophyses of first sacral vertebrae Width across posterior zygopophyses of last sacral vertebrae Transverse diameter of one ilium

AC C

EP

TE D

M AN U

SC

RI PT

ACCEPTED MANUSCRIPT

AC C

EP

TE D

M AN U

SC

RI PT

ACCEPTED MANUSCRIPT