Some fossilized friends from the Pliocene Purisima Formation of Santa Cruz

 

The extinct sand dollar species Dendraster ashleyi / D. gibbsii and the crab Cancer sp.

The Giant Carnivorous Sea Snail Clinopegma stantoni

The story of Clinopegma stantoni has been simmering here in Santa Cruz County for the past 116 years but is one that has been 5 million years in the making!  A little background on the name and history of this giant sea snail: Clino refers to slope and pegma is peg = pointed stick  The species is named in honor of Dr. Timothy W. Stanton, chief paleontologist. United States Geological Survey, whose work on Mesozoic faunas is well known.

The genus Clinopegma was named by Ulysses S. Grant, IV and Hoyt Rodney Gale published in 1931 in their monumental work on Pliocene and Pleistocene fossil mollusks of California.  Interestingly, here, U.S. Grant the IV, was the grandson of Ulysses S. Grant the first, president of the United States.  His grandson became a distinguished professor of paleontology at Berkeley

With regards to Clinopegma stantoni the species was named by Ralph Arnold in 1908 from the Año Nuevo park on the south side of the point in the upper member of the Purisima Fm. between Tunitas Creek and Pescadero Creek and near Ano Nuevo Creek in San Mateo County and also between New Brighton and Capitola beaches here in Santa Cruz and a couple other minor places and that’s it!

Coincidentally, Arnold also named a brand new species of Brittle Star, Amphiura sanctaecrucis that very same year of 1908 and that was discovered high up in the Santa Cruz Mountains and recently re-discovered en masse, dozens of individuals, in what’s called a brittle bed, but more on that in the movie…

Pacific Paleontology teams with California State Parks and the Santa Cruz Museum of Natural History for great weekend expeditions in search of ancient fossils

 Young and old alike had a wonderful time this past weekend on expeditions exploring for the fossilized remains of hundreds of creatures turned to stone in the rock layers of the ancient Monterey Bay and beyond with Pacific Paleontology, hosted by #CaliforniaStateParks and the #SantaCruzMuseumofNatural History.  If you or someone you know has an interest in paleontology, please contact @PacificPaleontology at https://dot.cards/papa for more information on our upcoming internship opportunities for youth and adults’ “Paleontologists in Training” programs this coming spring.

#FossilFriday, #Paleontologist, #paleontology, #pacificpaleontology, @pacificpaleontology, #beachfossils, #SantaCruz, #santacruzcounty, #fossil, #AnoNuevoStatePark, #LosOsos, #SantaCruzMuseumofNaturalHistory,

Grandicrepidula princeps, the Princess Slipper snail.

 

Good morning from Pacific Paleontology.  Here’s a recent 3-D scan we made of a fossil giant Grandicrepidula princeps, the Princess Slipper snail.  3D scanning has gotten a lot easier today, and we made this one with a simple app for iPhone called Photo Catch.  It took about 2 minutes to create from video and the app also has a Mac Desktop version and we use it frequently for these projects.  And even though I say the worms are parasites in the video, I'm not sure they actually caused the snail any harm; they may thus just be commensal as well.  Enjoy.

Screen washing sediments for macro- and micro-fossils

The end of our screen washing season is drawing to a close here at Pacific Paleontology with the approaching Winter rains here in Santa Cruz.  This is one of the Pliocene 4-5 million year old samples that we are running through our screen processing this week. 

A Three Dollar Morning

 

These are fossil Dendraster ashleyi or Dendraster gibbsii Sand Dollars from the

Purisima formation Here.  They are embedded in their original tomb along with

ghost shrimp burrows on the beach. These are about 5 million years old and I'm about

to extract them. Alright, here they are after I extracted them from their watery, sandy

tomb, they've been released to go back and be free again.  Back to the lab to be

prepared to go to the museum. Here we go.  This is back at our labs preparing the

sand dollars for their trip to the museum. Using glues (adhesives) and consolidants

(which are preservatives).  First we remove the sand from the sand dollars.  And the

sand has entombed them, like I said, for the last 5 million years.  And once that sand is

completely removed and brushed off, we'll apply a protective coating of consolidant

to harden the sand dollars which we're doing here.  Thanks for watching and enjoy

these beauties.  It was a three dollar morning.

#Paleontologist, #paleontology,  #SantaCruz, #Monterey, #santacruzcounty, #pacificpaleontology, @pacificpaleontology, #beachfossils, #fossil, #fossilhunting, #fieldwork, #beachcombing, #santacruzmuseum, #MontereyBay, #SCMNH, #universityofcaliforniamuseumofpaleontology, #UCMP, #californiaacademyofscience, #academyofscience,  #ucmpberkeley, 

False Alarm

 

Pacific Paleontology was recently called out to one of our paleo mitigation contract sites with the message that "bones have been found"!!  We excitedly arrived only to find this!  Neither paleontological nor archeological these bones, which were inadvertently moved from their original positions by the construction crew, are from a modern (Recent) Mule deer, Odocoileus hemionus and so not of historical importance for our team.  #paleontology, #SantaCruz, #santacruzcounty, #Monterey, #montereycounty, #paleontology, #mitigationpaleontology, #fossil, #pacificpaleontology, @pacificpaleontology, #Constructionsite, #fossilhunting, #archeology, #bones, 

“From the Ancient Sea, to the Rock, to the Lab, and Onward to the Museum”

 

This is WT967; the extinct sand dollar Dendraster ashleyi (Arnold, 1907) or Dendraster gibbsii (Rémond, 1863).  Discovered in May 2024 embedded in its 5 million year old sandy seafloor tomb, now turned to stone on a Santa Cruz beach, this specimen has been prepared and is on on its way to the Department of Invertebrate Geology at the California Academy of Sciences in San Francisco as a small component of our scientific research into the paleontology and evolution of life in the ancient Monterey Bay.  We are additionally examining the Pliocene current-protected sediments from under these ancient sand dollars for microscopic fossilized plankton called foraminifera to help us refine the age and environments that these faunas represent.  Very exciting ongoing research happening here at Pacific Paleontology Labs.

 

Rare 4-petal mutation of the sand dollar Scutellaster oregonensis (Clark, in Dall, 1909) recently donated to our paleontological research by beachcomber and collector Wendy Frye and identified by Richard Mooi of the @California Academy of Sciences in San Francisco. This is from the Purisima Formation here in Santa Cruz and is on the order of 2-3 million years old. As you may recall, echinoids typically have pentagonal (5-part) symmetry, making this discovery on par with a 4-leaf clover. This one is on its way to the paleontology collections of the Academy tomorrow on my monthly migration. Thank you Wendy!

"Sand Dollars Under the Sea: Fossil Sand Dollar Extraction and Prep"

 

This is an example of Dendraster ashleyi or Dandraster gibbsii; we believe the two are synonymous.  This is one of the most common fossil sand dollars found in Santa Cruz.  There are some other specimens from our area that look more closely like Dendraster excentricus but those are extremely rare, only two specimens are known, and there is another species in a different genus called Scuttellaster of the species oregonensis that are found more commonly in the south bay but these are beautiful fossils; They are all extinct species, no longer living today, and they are gorgeous to find along the beach especially in the strand line, and just very beautiful.  The genus Dendraster living today out in the Bay form big colonies on the bottom of the ocean if you dive down under surface you can see them there forming a purple carpet, all nestled in the sand at about a 45-degree angle.  Here's one of the living species on the left hand side and on the right is the fossil, probably ancestral to the modern one.

#paleontologist, #paleontology, #SantaCruz #santacruzcounty #pacificpaleontology

Pacific Paleontology #FossilFriday #beachfossils #fossils #fossilhunting

#fieldworkresearch #beachcombing #santacruzmuseum #montereybay

#scmnh #universityofcaliforniamuseumofpaleontology #ucmp

#californiaacademyofsciences #academyofsciences #ucmpberkeley

#lacmip #nhmla #fosssilprep #paleo #purisima #PurisimaFormation #sanddollar

#fosssilprep #paleo #purisima

“Pacific Paleontology Recognized by the California Small Business Develpment Center, SBDC”

https://calcoastalsbdc.com/success-stories/pacific-paleontology-papa 

I am pleased to announce that Pacific Paleontology has been chosen to be featured by the California Small Business Development Center as a Developing Success Story!  I could not be more pleased by this recognition for all our hard work that we have been doing over the past year!  The CalCoastalSBDC, the central California arm of the statewide organization, has been instrumental in our successes so far, in addition to helping our firm successfully acquire a $5,000.00 startup grant from the state!  With these funds we have been able to purchase much-needed equipment to fill important gaps in our collecting, prepping, and archiving abilities as well as onboard essential business insurance.  Here you can see some of the field and lab equipment used to extract and prepare the fossils.  Large new acquisitions from the British firm Zoic for our “Velociraptor” and “TRex” laboratory air scribes and from Eastwing and Zog for our field hand tools.  And of course big shoutouts to @Austin Hendy, @Charles L Powell, @Bobby Boessenecker, #lacmip, #santacruzmuseum, #ucmp, the #californiaacademyofsciences, and so many others for their ongoing instrumental support.

#Paleontologist, #paleontology,  #SantaCruz, #Monterey, #santacruzcounty, #mitigation, #mitigationpaleontology, #pacificpaleontology, @pacificpaleontology, #fossil, #fossilhunting, #fieldwork, #santacruzmuseum, #MontereyBay, #SCMNH, #universityofcaliforniamuseumofpaleontology, #UCMP, #californiaacademyofscience, #academyofscience, #ucmpberkeley, #LACMIP, #NHMLA, #Monterey, #fosssilprep, #paleo, #montereycounty, #fossil, #Constructionsite, #fossilhunting,

 “And… That’s a Wrap”

We are wrapping up our first paleontological mitigation contract here in my hometown of Scotts Valley and we took this opportunity for a promotional marketing photoshoot over the weekend for our new business website.  Pacific Paleontology was hired to monitor a small subdivision construction project here that involved digging down into the Santa Margarita Formation layer of rock, which is about 10-12 million years old.  This is a rock layer that is common in our area, is one that I have been studying here for the past four decades, and have discovered many hundreds of fossils from, primarily sharks.  The marine vertebrate fauna includes toothed and baleen whales, sharks, fish, rays, skates, dolphins, porpoises, sea turtles, birds, pinnipeds (eared and earless seals and primitive walruses), sirenians, and desmostylians, among others.  Marine clams, snails, and other invertebrates also occur here and are highly diverse in the local region.  Terrestrial vertebrates, such as camels and horses, as well as rare woody plants are also known to occur in the Santa Margarita.  No fossils were uncovered during construction in the massive medium-grained unconsolidated sands that used to make up the bottom of the ocean here.  Now that the grading is completed, Pacific Paleontology is tasked with producing the reports that will show compliance of the project to federal, state, and local legislation for the conservation of protected historical resources.  These regulations are relatively new within the past 20 years, and our understanding of the evolutionary history of life in California and elsewhere has advanced significantly due to the recovery of fossils through these protections.  As a coincidental aside, I worked closely onsite with Tracy Miller of MTM Tractor.  As it turns out, Tracy and I have a history together!  The last time we saw each other he was in jr. high and I was in high school and we were working together at a local restaurant in town; so we had some catching up to do!  Small world!!!

For more information on the fossils of the Santa Margarita Formation check out our video on the Santa Cruz Museum of Natural History website: https://www.santacruzmuseum.org/naturalist-night-santa-cruz-sandhills/ 

#Paleontologist, #paleontology,  #SantaCruz, #mitigation, #mitigationpaleontology, #pacificpaleontology, #fossil, #fossilhunting, #santacruzmuseum, #fosssilprep, #fossil, #scottsvalley, #Miocene, #SantaMargarita, #SantaMargaritaFormation, 

 

“How Old Do You Think That Mastodon Is?”

 

I am incredibly excited to announce that after 42 years since its initial discovery, the Aptos Mastodon, Mammut sp., on exhibit at the Santa Cruz Museum of Natural History, will be formally getting C-14 dated in the coming weeks! Discovered in a creekbed by then-high school student James Stanton, who was searching for antique bottles in the water just after the heavy storm surge of 1980, the skull has been on exhibit at the museum for the past 40 years. Fast forward to this week and the bone and plant samples, once I get them cleaned with distilled water of any attached sediment or other materials sticking to them, will be sent off to NOSAMS the National Ocean Sciences Accelerator Mass Spectrometry Lab, which is a part of Woods Hole Oceanographic Institution!  The three samples will consist of a fragment of the bone from the inside of the mastodon’s skull, called pneumatic bone due to its looking like swiss cheese, an exterior fragment of skull bone, and a piece of carbonized wood that was discovered in contact with the bone around the skull all those years ago.  Specimens need to be younger than 50,000 years before present in order for the C-14 process to work, anything older and an indeterminate age is assigned.  Back in 1980, during the reconstruction of the mastodon’s skull, the two largest pieces of its skull were painstakingly reunited over a two-year period, with hundreds of fragments leftover from the process.  In true museum detective story fashion, the box that all the fragments were stored in remained unaccounted for over the past 3 years, until I was contacted last week with the amazing news that the box, untouched since I packed it away 40 years ago (see pics below), had been discovered once again!  The river gravels that the skull was preserved in, an incredibly rare process, have never been absolutely dated, only relatively dated.  What this means is that we might be able to assign an exact age to the mastodon and river sediments, if they are younger than 50,000 years old, instead of having a rough estimate of their age based on other rock layers nearby.  And if the mastodon samples come back with an indeterminate age, that is also important information, for then we will be able to say that the sediments, and the mastodon, are older than 50k!  And for those of you who may be wondering why in the world would the inside of a mastodon’s skull look like swiss cheese, well it has to do with biomechanics.  All proboscideans; mammoths, mastodons, and elephants, have pneumatic bone (see sample pic below), or skull bone with large “air pockets” in it rather than solid bone due to it being much lighter than solid skull bone and yet still strong.  Think of all that weight that the proboscidean has to hold up and out; so the lighter the better!   Stay tuned in the coming weeks after the tests come back to learn… the rest of the story!

https://www.santacruzmuseum.org/ 

http://www.jstantonphotography.com/-home.html 

https://www2.whoi.edu/site/nosams/ 

#Paleontologist, #paleontology,  #SantaCruz, #Monterey, #santacruzcounty, #mitigation, #mitigationpaleontology, #pacificpaleontology, @pacificpaleontology, #fossil, #fossilhunting, #fieldwork, #santacruzmuseum, #MontereyBay, #SCMNH, #universityofcaliforniamuseumofpaleontology, #UCMP, #californiaacademyofscience, #academyofscience,  #ucmpberkeley, #fosssilprep, #paleo, #fossil, #fossilhunting, #Research, #fossilpreservation, #vertpaleo, #museumcuration, #collectionsmanagement, #fossilcollection, #fossilcollector, #fossilconservation, #santacruz, #Mastodon, #Proboscidean, #C-14dating, #Holocene, 

“Rock Removal is About to Get a Lot Easier!”

 

When a fossil is found in the rock, paleontologists don’t actually just dig the fossil itself out of the rock but they remove it along with a block of the surrounding rock, called matrix, to later be prepared further in the lab. Like this 4 million year old ?Macoma sp. clam you see here, the matrix needs to be carefully cut back or completely removed, depending upon the fragility of the fossil.  Here you see traditional hand pick removal of the matrix, which fine-tunes the block for later compact storage in a public museum!  That method is about to be augmented with pneumatic help.

With our new small business development grant I’ll be purchasing two new air scribes; the “Velociraptor Mark II” and the “T. rex” from Zoic Palaeotech.  I’ve wanted air scribes for quite awhile, but have never been able to afford them for prep work until now!  Looking forward to upping my prep game now that my business is off the ground.

zoicpaleotech.com/ 

Patterns & Processes in Rockfall Dynamics from 1977-2022

 

The author in about 1977.  My dog Blackie in the foreground.

Since 1977 when I was 17 I have been fascinated by the dynamic nature of our coast here along the Monterey Bay.  I can never go down to the same shore twice; it’s in constant flux, never the same as it was the day before.  One of the things that I have been tracking as a paleontologist here are the rockfalls that are continually happening as a coastal erosional process.  These rockfalls are singularly amazing, not only in

Capitola Beach looking toward New Brighton, early 1900's and 2019.

their size and scope, but in the history of our bay that they reveal.  With each new fall, like turning the pages of a book, new information comes to light and a more complete picture of the history of our bay begins to form in my mind.  This process is a decadal revelation; only imaginable over long periods of time, with emergent information coming to light in the longer scale that is not visible from year to year.  Not year-to-

The scale of some of these rockfalls is immense.  Here is Susan for perspective.

year; but more expansive time over 10-, 20-, 30-, and 40-years that allows one to understand geological time, Deep Time, better.  With each turn of the page, new and varied creatures are revealed that were not known before and more details of the ancient physical oceanography of the California coast emerges with each new strata set that comes to the light of day.  Interacting with a single place over a large expanse

My dog Blackie and I taking a break from prospecting, The Point, 1980.

of time such as this can engage one in processes that are not visible in the day to day.  There is a larger periodicity of non-random dynamic processes that overlies a place such as this.  Some of those processes present themselves to me, others may only be inferred over even larger expanses of time, not known to a single life span.  I will end with a quote from one of my favorite authors, Pulitzer Prize winning Wallace Stegner

Rockfall 10.20 is a series of interconnected and developmentally related rockfalls, 2020.

who has written some of my most comforting literature on the American west.  I came to know Wallace, or rather his writing, through my father, who I did not really know at all in the sense of “father” since he past away when I was 5.  From a longing to know who my father was, I was introduced to Wallace, since my father and Wallace

grew up in the same small Canadian town together, Eastend, in the early 1900’s.  In reading the words of Stegner it allowed me to feel close to the father I never knew, and at the same time allowed me to learn an appreciation for a sense of place.  This is a quote from one of Wallace’s last essays, the year before he died at age 84; from “The

Sense of Place” by Wallace Stegner. Copyright 1992 by Wallace Stegner. Reprinted by permission of Random House, Inc. “So I must believe that, at least to human perception, a place is not a place until people have been born in it, have grown up in it, lived in it, known it, died in it – have both experienced and shaped it, as individuals, families, neighborhoods, and communities, over more than one generation. Some are born in their place, some find it, some realize after long searching that the place they left is the one they have been searching for. But whatever their relation to it, it is made a place only by slow accrual, like a coral reef.”  I hope you all have a strong sense of place, wherever that may be, however diversified, however tangible or conceptual. In this particular place on Earth I am comforted, because it recalls the work of Wallace Stegner, who in turn certainly knew my father, and by such circuitous routes I, too, can know my father.

#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, #fossilcollections, #museumcuration, #collectionsmanagement, #fossilcollection, #fossilcollector, #fossilconservation, #digitization, #onlinecollections, #Rockfalls, #Coastalerosion, #Dynamiccoast, #Landslide, #Stratigraphy, #GeologicalProcesses, #Geology,   #FossilFriday

Olivella's graveyard at Pandora's Cave!

Here is Olivella's Graveyard (now referred to the genus Callianax) at Pandora's Cave, New Brighton State Beach; the first shell bed unconformably overlying the finer sandstone layer immediately below it.  One can see here bivalves such as Leukoma and Macoma, a naticid, perhaps Natica clausa, and the Nassariids Demondia californicus and Nassarius.  Portions of this shell layer, which does not stretch continuously for the entire length of the section and is thus more aptly referred to as a Lag or Shell Bed or Lens, consists partly of concreted shell blobs and loosely concentrated shells in which the gastropods are preserved mostly whole and the bivalves are predominantly broken prior to burial.  Olivella's Graveyard represents a moderately shallow water (27-46m) storm deposit and is one of many dozens of examples of "missing time", or  unconformities, in the evolutionary record of our Monterey Bay where once-existing layers have been eroded away by storms during the Pliocene Period about 3 million years ago, never to be seen again.

#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

Life's Perfect Circle...

 

I am happy to share that I’m adding a new position as Paleontology Collections Advisor at the Santa Cruz Museum of Natural History to my schedule! I officially began my career as a paleontologist with the museum 46 years ago now, in 1976 when I was 16. It brings me unparalleled joy to now be working with the museum once again, completing my life's circle with the original institution that I began with all those years ago. https://www.santacruzmuseum.org/

#Paleontologist, #paleontology, #pacificpaleontology, #beachfossils, #SantaCruz, #santacruzcounty, #fossil, #museum, #fossilhunting, #fieldwork, #beachcombing, #santacruzmuseum, #MontereyBay, #SCMNH, #digitization, #museumcollections, #fosssilprep, #paleo, #fossil, #Research, #career, #share #foundartifacts, #fossilpreservation, #invertpaleo, #vertpaleo, #taphonomy, #fossilcollections, #museumcuration

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