scholarly journals A new marine vertebrate assemblage from the Late Neogene Purisima Formation in Central California, part II: Pinnipeds and Cetaceans

Geodiversitas ◽  
2013 ◽  
Vol 35 (4) ◽  
pp. 815-940 ◽  
Author(s):  
Robert W. Boessenecker
Keyword(s):  
Central California ◽  
Late Neogene ◽  
Vertebrate Assemblage

Age, Stratigraphy, and Correlations of the Late Neogene Purisima Formation, Central California Coast Ranges

2007 ◽  
Author(s):  
Charles L. Powell ◽  
John A. Barron ◽  
Andrei M. Sarna-Wojcicki ◽  
Joseph C. Clark ◽  
Frank A. Perry ◽  
...  
Keyword(s):  
California Coast ◽  
Central California ◽  
Late Neogene ◽  
Coast Ranges ◽  
California Coast Ranges

scholarly journals Latest Pacific basin record of a bony-toothed bird (Aves, Pelagornithidae) from the Pliocene Purisima Formation of California, U.S.A.

2018 ◽  
Author(s):  
Robert Boessenecker ◽  
N. Adam Smith
Keyword(s):  
Volcanic Rocks ◽  
Pacific Basin ◽  
Central California ◽  
Geologic Time ◽  
Northeast Pacific ◽  
The Pacific ◽  
Late Neogene ◽  
Early Late ◽  
A New Species

Fossils of pelagornithids (bony-toothed birds) have been reported from strata of Paleocene to Pliocene age, and from every continent. The extreme fragility of pelagornithid bones has no doubt contributed to their geographically and temporally sporadic record, and thus it has been difficult to appreciate any long-term phylogenetic trends through geologic time for this group. We report a well-preserved partial humerus of the gigantic bird Pelagornis from the late Neogene Purisima Formation of central California. Due to its incompleteness, we refrain from naming a new species. This fossil is fortuitously bracketed by two ash beds, which have been correlated with volcanic rocks at 3.35 ± 0.05 Ma and 2.5 ± 0.2 Ma, indicating a middle to late Pliocene age for this fossil. This fossil extends the record of the pelagornithids in the Northeast Pacific, previously only known up until the early late Miocene (10–12 Ma). This fossil is the latest record of a pelagornithid for the Pacific Basin, and additionally represents the latest reliably dated pelagornithid record worldwide. This record suggests that the pelagornithids survived until the end of the Pliocene, and became extinct during the ocean restructuring and climatic upheavals that caused the demise of many other groups of marine vertebrates at that time.

Effects of marine reserves on predator-prey interactions in central California kelp forests

2020 ◽  
Vol 655 ◽  
pp. 139-155
Author(s):  
DC Yates ◽  
SI Lonhart ◽  
SL Hamilton
Keyword(s):  
Species Interactions ◽  
Size Structure ◽  
Marine Reserves ◽  
Mortality Rates ◽  
Kelp Forests ◽  
Negative Effects ◽  
Central California ◽  
Invertebrate Predators ◽  
Predatory Fishes ◽  
Density And Biomass

Marine reserves are often designed to increase density, biomass, size structure, and biodiversity by prohibiting extractive activities. However, the recovery of predators following the establishment of marine reserves and the consequent cessation of fishing may have indirect negative effects on prey populations by increasing prey mortality. We coupled field surveys with empirical predation assays (i.e. tethering experiments) inside and outside of 3 no-take marine reserves in kelp forests along the central California coast to quantify the strength of interactions between predatory fishes and their crustacean prey. Results indicated elevated densities and biomass of invertebrate predators inside marine reserves compared to nearby fished sites, but no significant differences in prey densities. The increased abundance of predators inside marine reserves translated to a significant increase in mortality of 2 species of decapod crustaceans, the dock shrimp Pandalus danae and the cryptic kelp crab Pugettia richii, in tethering experiments. Shrimp mortality rates were 4.6 times greater, while crab mortality rates were 7 times greater inside reserves. For both prey species, the time to 50% mortality was negatively associated with the density and biomass of invertebrate predators (i.e. higher mortality rates where predators were more abundant). Video analyses indicated that macro-invertivore fishes arrived 2 times faster to tethering arrays at sites inside marine reserves and began attacking tethered prey more rapidly. The results indicate that marine reserves can have direct and indirect effects on predators and their prey, respectively, and highlight the importance of considering species interactions in making management decisions.

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