New record of a previously unknown species from the Pliocene of Monterey Bay!

WY890.1: Turcica brevis was described from the the Pliocene of the Central Valley but this is the first record from Monterey Bay! .

 

“An Ancient Skate of Monterey Bay”

 

This is WT744, the *upper jaw*, or palatoquadrate, from the skull of a 2-3 million year old skate, related to stingrays, from the ancient Monterey Bay. Its scientific name is Raja sp cf. R. binoculata. It was discovered in one of the now well-known and most favorite layers, or shell beds, in the upper part of the Purisima Formation of Santa Cruz, CA. The other creatures that this skate was preserved alongside of include Princess Slipper snails (Grandicrepidula princeps), Arc Clams (Anadara trilineata), Giant Barnacles (Balanus aff. B. proxinubilus), and many others, and all represent a nearshore environment for this creature. In point of fact, when Chaco and Yoshi and I are out in the water on the modern reef here we can still disturb living skates resting on the bottom; they then gently flap their flippers up into the floating kelp fronds and it’s always an exciting meeting for all of us.

The rock that it came from had what we call “rip clasts” in it: chunks of angular mudstone that were broken off, or ripped, from the layer of mudstone below it during an erosional event, or regression, representing a period where there was a lowering of sea level. We have now mapped several dozen of these erosional events, called unconformities, preserved in our study area. All together they represent the dynamic geological history of our bay, itself mirroring the dynamic changes happening Globally over deep time and thus influencing and creating a dynamic biological evolutionary history as a result.

This upper jaw is not actually bone, but rather the cartilage precursor of bone found in all sharks, skates, and rays. Being soft rather than hard like bone, cartilage is less likely to be preserved in the fossil record and more rare. In fact, body cartilage of sharks, skates, and rays is even rarer and not found here at all as far as I know; presumably because mouth cartilage had to be slightly more calcified and hard structurally to do its job, and thus preserved more commonly. You will notice in the beginning of the video the hexagonal pattern of the fossilized jaw tissue that is a key feature of fossilized cartilage.

#Paleontologist, #paleontology, #pacificpaleontology, @pacificpaleontology, #beachfossils, #SantaCruz, #santacruzcounty, #fossil, #fossilhunting, #fieldwork, #beachcombing, #santacruzmuseum, #MontereyBay, #SCMNH, #mitigationpaleontology, #universityofcaliforniamuseumofpaleontology, #UCMP, #californiaacademyofscience, #academyofscience,  #ucmpberkeley, #LACMIP, #NHMLA, #sierraclub, #Monterey, #fosssilprep, #paleo, #montereycounty, #Purisima, #PurisimaFormation, #fossil, #gastropod, #Constructionsite, #fossilhunting, #collectingtechniques, #Bivalve, #Research, #Pliocene, #foundartifacts, #fossilpreservation, #invertpaleo, #vertpaleo, #taphonomy, #FossilFriday

“An Example of Remarkably Well-Preserved fossils”

 

Sometimes creatures are preserved astonishingly well that it boggles the mind!  From Dinosaur skin impressions, to frozen mammoths and glass insect fossils, the world of fossil preservation is incredibly bewildering!  And such was the case with the whole, unfilled, baby Arc Clams, Anadara trilineata, shown here.  Preserved so well, without a gap between the two valves of the shell, no ocean sediment filled into the inner area of the shell and the shells are “empty”.  These shells were likely moved very little from their original burial spot, so as to preserve both valves together.  Almost universally, fossil clams are discovered with sediment-filled interiors, meaning they were moved around on the bottom of the sea floor before being buried.  Even clams that are preserved “in-situ” or in life-position are usually preserved with sediment filling inside the two valves, making these clams extremely exceptionally, uber rare.  Additionally, almost universally the surrounding rock exerts a degree of pressure on a fossil and can even break, squish, or completely pulverize the organism.  

These Arc Clams seem to have avoided that.  Clams can live either in the sediment, or infaunal, or on the sediment, or epifaunal, at the bottom of the ocean; the two most common lifestyles–there are others.  This particular species lived just below the sediment-water interface.  Reconstructing the ancient lifestyle of this clam was the focus of one of my earliest research papers as a young paleontologist at U.C. Berkeley back in 1984.  I was able to use the commensal marine Polychaete worm Polydora, which leaves a scar on the shell of Anadara, as a proxy measure to reconstruct the lifestyle orientation of these ancient fossils from 4 million years ago.  Commensalism is when two creatures share an ecological relationship that neither harms (parasitism) nor benefits (symbiosis) the two species involved.  The link to the manuscript, and some of the diagrams used, appear below.

Thompson, W., 1984.  Anadara from the Purisima Formation along the Monterey Bay

#Paleontologist, #paleontology, #pacificpaleontology,

@pacificpaleontology, #beachfossils, #SantaCruz,

#santacruzcounty, #fossil, #fossilhunting, #beachcombing,

#santacruzmuseumofnaturalhistory, #SCMNH,

#universityofcaliforniamuseumofpaleontology, #UCMP, #CAS,

#californiaacademyofsciences, #Monterey, #montereycounty,

#mitigationpaleontology, #Purisima, #PurisimaFormation,

#fossil, #gastropod, #Constructionsite, #fossilhunting,

#collectingtechniques, #Bivalve, #Research, #Pliocene,

#foundartifacts, #fossilpreservation, #taphonomy

Looking into the eye of the next big storm?

Capitola winter storm waves, 1-13-2019;

Engaging others, whether it be students in their classrooms or the public, in scientific dialogue over global-scale natural science topics is one of the great unspoken duties, in my mind, of scientists and educators. And nowhere is that at once easier and more difficult than with climate, and specifically with ocean-atmosphere interactions that manifest in the regular cycles we call “El Nino and La Nina”. These cycles are regulated by changes in, and interactions between, sea surface temperature, rainfall, air pressure and temperature, and ocean and atmospheric circulation. Of course, in conversations with both students in the classroom and friends and family, these processes can be broken down further into basic ideas of volume, mass, density, temperature, pressure, and so on.

The idea of climate and oceanic oscillations doubtless began prior to the 1800’s, but the idea of El Nino/La Nina cycles, at least in the Pacific, started when fishermen on the coast South America, in Peru, noticed warm ocean currents appearing around Christmas time every few years. Referring to the birth of Christ, they nicknamed the events “El Nino”, which is of course “the boy” in Spanish. Fishing here is best in La Nina years, when cold upwelling ocean water drives rich nutrients to the surface from the deep.

An El Niño occurs when surface water in the equatorial Pacific becomes warmer than average and east winds blow weaker than normal. The opposite condition is called La Niña: water that is cooler than normal and the east winds are stronger. El Niños typically occur every 3 to 5 years. NOAA “El Nino and La Nina”

We are currently in an uncommon “Triple La Nina”. Here’s an out take from the journal “Nature”: “The current [2022] La Niña started around September 2020 and has been mild-to-moderate most of the time since then. As of April 2022, it intensified, leading to a cold snap over the eastern equatorial Pacific Ocean not seen at that time of year since 1950. “That’s pretty impressive,”…

The latest forecast from the World Meteorological Organization, issued on 10 June, gives a 50–60% chance of La Niña persisting until July or September… NOAA’s Climate Prediction Centre has forecast a 51% chance of La Niña in early 2023.

…this prolonged La Niña, unlike previous triple dips, hasn’t come after a strong El Niño, which tends to build up a lot of ocean heat that takes a year or two to dissipate1. “I keep wondering, where’s the dynamics for this?” …” Nature News, 23 June, 2022

One of the advantages of living so close to the ocean is to be intricately connected to these cycles, and being engaged in one spot, one relatively small chunk of land, for many decades is that one can experience these cycles and feel their presence and effect on the land, the ocean, the weather, the climate, and the community. We are indeed very fortunate to live where we do!

The two tables and data are courtesy of https://ggweather.com/enso/oni.htm

2014: Weak El Nino

2015: Very Strong El Nino

2016: Weak La Nina

2017: Weak La Nina

2018: Weak El Nino

2019: Weak El Nino to Enso Neutral (in Between El/La)

2020: Moderate La Nina

2021: Moderate La Nina

2022:

#Paleontologist, #paleontology, #pacificpaleontology, @pacificpaleontology, #beachfossils, #SantaCruz, #santacruzcounty, #fossil, #fossilhunting, #beachcombing, #santacruzmuseumofnaturalhistory, #SCMNH, #universityofcaliforniamuseumofpaleontology, #UCMP, #CAS, #californiaacademyofsciences, #Monterey, #montereycounty, #mitigationpaleontology, #Purisima, #PurisimaFormation, #fossil, #gastropod, #Constructionsite, #fossilhunting, #collectingtechniques, #Bivalve, #Research, #Pliocene, #foundartifacts, #FossilFriday

 

Oh for '70's days gone by...

 

Two months out pre-pandemic hordes, January 11th, 2020. Oh for '70's days gone by... #Paleontologist, #paleontology, #SantaCruz, #santacruzcounty, #Monterey, #montereycounty, #paleontology, #beachfossils, #mitigationpaleontology, #Purisima, #PurisimaFormation, #fossil, #gastropod, #pacificpaleontology, @pacificpaleontology, #Constructionsite, #fossilhunting, #collectingtechniques, #Bivalve, #Research, #Pliocene

Meanwhile, Back at the Paleo Prep Lab

 Once fossils are blocked out of the rock in the field, those blocks with the fossils inside are brought back to the lab. Once there, as in this case with this Macoma sp. clam (WT892.14) (not a Cryptomya), paleontologists will begin to dig and prepare underneath the fossil to release it completely from its rocky tomb. This can only be done with the most robust fossils; many are so delicate that they need to remain in their original rocky blocks. Once the fossil is completely cleaned of sediment it can be preserved with liquid consolidant that soaks into it and which will harden and preserve the fossil for many decades of research in the museum. Finally, it is recorded numerically, which corresponds to the descriptive data on where and when it was discovered! #Paleontologist, #SantaCruz, #Monterey, #paleontology, #beachfossils, #mitigationpaleontology, #Purisima, #PurisimaFormation, #fossil, #gastropod, #pacificpaleontology, @pacificpaleontology, #Constructionsite, #fossilhunting, #collectingtechniques, #Bivalve, #Research, #Pliocene.

Aladdin's Lamp Comes to Life

 This fossil clam is named Yoldia cooperi (Gabb, 1865), is approximately 4 million years old, and is found occasionally in the Purisima Formation along Monterey Bay. The genus Yoldia is named in honor of D. A. D.'Aquirra e Gadea, Count of Yoldi, a Danish shell collector. I'm not sure who Cooper was. I enjoy discovering this beautiful clam species because of its fine sculpture, its thin shell (which makes it challenging to collect unbroken so it keeps my skill set sharp), and its whimsical similarity to an Aladdin's Lamp! Also interesting and making it completely unique from all other mollusks in the Purisima is this species' long row of many fine hinge teeth and alternating sockets found along the majority of the dorsal margin of the shell, shown in the second photo above. Today, Yoldia cooperi lives in the eastern Pacific from Humboldt County to Baja California Sur and in fine sediments from 5 to 40 meters. Its habitat has likely not changed much in the past 4 million years, as it is found entombed in fine to medium sandstones of the Purisima as well. Shown here with some of the tools needed to extract it safely from the rock, including the consolidant; a liquid hardening compound. This particular specimen at the top was extracted over a period of several days in order to allow the successive applications of consolidant to fully dry before moving the specimen from its tomb. WT730 (Below), WT765 (Above). #Paleontologist, #Santa Cruz, #Monterey, #paleontology, #beach fossils, #Purisima, #Purisima Formation, #fossil, #pacific paleontology, @pacificpaleontology, #fossil hunting, #collecting techniques, #Bivalve, #Research, #Pliocene,