PYGMY MAMMOTHS FROM SAN MIGUEL ISLAND, CALIFORNIA

1998 ◽  
Author(s):  
Robert S. Gray ◽  
William H. Harz
Keyword(s):  
San Miguel Island

Beads, Bifaces, and Boats: An Early Maritime Adaptation on the South Coast of San Miguel Island, California

2005 ◽  
Vol 107 (4) ◽  
pp. 677-683 ◽  
Author(s):  
JON M. ERLANDSON ◽  
TODD J. BRAJE ◽  
TORBEN C. RICK ◽  
JENNA PETERSON
Keyword(s):  
South Coast ◽  
The South ◽  
San Miguel Island

scholarly journals Intrashell Radiocarbon Variability in Marine Mollusks

Radiocarbon ◽  
2006 ◽  
Vol 48 (3) ◽  
pp. 387-400 ◽  
Author(s):  
Brendan J Culleton ◽  
Douglas J Kennett ◽  
B Lynn Ingram ◽  
Jon M Erlandson ◽  
John R Southon
Keyword(s):  
Deep Ocean ◽  
Mytilus Californianus ◽  
Ocean Water ◽  
Santa Barbara Channel ◽  
Santa Barbara ◽  
Complex Product ◽  
Deep Ocean Water ◽  
San Miguel Island ◽  
Ams Dating ◽  
Channel Region

We demonstrate variable radiocarbon content within 2 historic (AD 1936) and 2 prehistoric (about 8200 BP and 3500 BP) Mytilus californianus shells from the Santa Barbara Channel region, California, USA. Historic specimens from the mainland coast exhibit a greater range of intrashell variability (i.e. 180–240 14C yr) than archaeological specimens from Daisy Cave on San Miguel Island (i.e. 120 14C yr in both shells). δ13C and δ18O profiles are in general agreement with the up welling of deep ocean water depleted in 14C as a determinant of local marine reservoir correction (ΔR) in the San Miguel Island samples. Upwelling cycles are difficult to identify in the mainland specimens, where intrashell variations in 14C content may be a complex product of oceanic mixing and periodic seasonal inputs of 14C-depeleted terrestrial runoff. Though the mechanisms controlling ΔR at subannual to annual scales are not entirely clear, the fluctuations represent significant sources of random dating error in marine environments, particularly if a small section of shell is selected for accelerator mass spectrometry (AMS) dating. For maximum precision and accuracy in AMS dating of marine shells, we recommend that archaeologists, paleontologists, and 14C lab personnel average out these variations by sampling across multiple increments of growth.

Ants as first intermediate hosts of Mesocestoides on San Miguel Island, USA

2005 ◽  
Vol 79 (1) ◽  
pp. 67-73 ◽  
Author(s):  
K.A. Padgett ◽  
W.M. Boyce
Keyword(s):  
Intermediate Host ◽  
Dna Sequences ◽  
Field Studies ◽  
Lasius Niger ◽  
Deer Mice ◽  
Intermediate Hosts ◽  
Island Fox ◽  
San Miguel Island ◽  
Pooled Samples ◽  
First Intermediate Host

AbstractThis study tested the hypotheses that ants (Formicidae) function as a first intermediate host of Mesocestoides (Cestoda: Mesocestoididae) and that deer mice (Peromyscus maniculatus) develop metacestode infections after ingesting cysticercoid or procercoid-infected ants. Field studies were conducted at an island fox (Urocyon littoralis littoralis) breeding facility located on San Miguel Island, California Channel Islands National Park, USA, where >40% of captive foxes were infected with adult Mesocestoides. Eight percent (8%) of deer mice at the fox pen site were infected with Mesocestoides metacestodes while none were infected at a distant site where foxes were absent (campground), thereby indicating the potential localized presence of a first intermediate host. To test whether ants from San Miguel Island contained Mesocestoides DNA, a polymerase chain reaction (PCR)-based diagnostic assay was developed using nested primers that could detect a single hexacanth larva within pooled samples of ten ants. Ants (Lasius niger and Tapinoma sessile) collected near the fox breeding facility were tested using the nested-PCR assay. Seven of 223 pooled samples of L. niger (3.1%) and 2 of 84 pooled samples of T. sessile (2.4%) tested positive for Mesocestoides DNA, while none of the ants were positive at the campground site. Positive samples were sequenced and found to match DNA sequences from Mesocestoides obtained from island fox and deer mice. Finally, to determine whether ants function as a first intermediate host for Mesocestoides, colony-raised deer mice (n=47) were fed L. niger (n=3860) or T. sessile (n=339) collected from the San Miguel Island fox breeding facility. No mouse became infected with Mesocestoides metacestodes after ingesting ants. While both L. niger and T. sessile from SMI were positive for Mesocestoides DNA, they were not infective to deer mice in the laboratory.

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