The mid-Irvingtonian Fairmead Landfill fossil site, Madera County Paleontology Collection, and Fossil Discovery Center of Madera County, California

Author(s):  
Robert G. Dundas ◽  
James C. Chatters
Keyword(s):  
2015 ◽  
Vol 3 (2) ◽  
Author(s):  
Mr. Daniel Kipkorir ◽  
Prof. Simiyu Wandibba
Keyword(s):  

2018 ◽  
Author(s):  
Sarah W. Keenan ◽  
◽  
Jennifer M. DeBruyn ◽  
Chris Widga

2016 ◽  
Vol 53 (6) ◽  
pp. 591-604 ◽  
Author(s):  
Cale A.C. Gushulak ◽  
Christopher K. West ◽  
David R. Greenwood

Early Eocene fossil floras from British Columbia are a rich resource for reconstructing western North American early Cenozoic climate. The best known of these floras reflect cooler (MAT ≤ 15 °C) upland forest communities in contrast to coeval (MAT ≥ 18 °C) forests in lowland western North American sites. Of particular interest is whether Early Eocene climates were monsoonal (highly seasonal precipitation). The McAbee site is a 52.9 ± 0.83 Ma 0.5 km outcrop of bedded lacustrine shale interbedded with volcanic ash. In this report two historical megaflora collections that were collected independently from different stratigraphic levels and (or) laterally separated by ∼100–200 m in the 1980s (University of Saskatchewan) and 2000s (Brandon University) are investigated to (i) assess whether they represent the same leaf population, (ii) assess whether a combined collection yields more precise climate estimates, and (iii) reconstruct paleoclimate to assess the character of regional Early Eocene precipitation seasonality. Combined, the two samples yielded 43 dicot leaf morphotypes. Analysis of leaf size distribution using ANOVA showed no difference between the two samples, and thus they were combined for climate analysis. Climate analysis using leaf physiognomy agrees with previous estimates for McAbee and other regional megafloras, indicating a warm (MAT ∼8–13 °C), mild (CMMT ∼5 °C), moist (MAP > 100 cm/year) ever-wet, non-monsoonal climate. Additionally, we recommend that climate analyses derived from leaf fossils should be based on samples collected within a stratigraphically constrained quarry area to capture a snapshot of climate in time rather than time-averaged estimates derived from multiple quarry sites representing different stratigraphic levels within a fossil site.


2009 ◽  
Vol 83 (2) ◽  
pp. 238-262 ◽  
Author(s):  
Richard C. Hulbert ◽  
Steven C. Wallace ◽  
Walter E. Klippel ◽  
Paul W. Parmalee

The previously poorly known “Tapiravus” polkensis Olsen, 1960 (Mammalia, Perissodactyla, Tapiridae) is now known from abundant, well preserved specimens from both the type area in central Florida and from the Gray Fossil Site (GFS) in eastern Tennessee. The latter has produced over 75 individuals, the greatest number of tapirids from a single fossil site, including many articulated skeletons. Almost all linear measurements taken on skulls, mandibles, and cheek teeth from GFS have coefficients of variation less than 10 (most between 3 and 7), indicating the presence of a single species. However, the sample reveals considerable intraspecific variation for a few key morphologic features, including development of the sagittal crest, outline shape of the nasals, and number and relative strength of lingual cusps on the P1. The Florida sample of T. polkensis is more limited, but has the same state as the GFS sample for all preserved characters of systematic significance, and while the Florida teeth are on average smaller (especially narrower lower cheek teeth), they fall either within or just below the observed range of the Gray Fossil Site population. The new material supports a reassignment of “Tapiravus” polkensis to the genus Tapirus, and demonstrates that the geologic age of the species is significantly younger than previously thought, Hemphillian rather than Barstovian. Tapirus polkensis is the smallest known North American Tapirus, and smaller than any of the extant species in the genus, with an estimated average mass of 125 kg.


Geoheritage ◽  
2017 ◽  
Vol 10 (3) ◽  
pp. 463-472 ◽  
Author(s):  
Hugo Martín Abad ◽  
Candela Blanco Moreno ◽  
Sandra Barrios de Pedro ◽  
Jesús Marugán-Lobón ◽  
Francisco José Poyato Ariza ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document