Origin of Cetaceans

0

New Addition to Web
The Evolution of Whales
Based on National Geographic's sensational article from November 2001, by Douglas H. Chadwick, Shawn Gould and Robert Clark, The Evolution of Whales. Overview of whale origins. Includes illustrations based on fossil progressions in transitional whales and dolphins. Additional comments from early whale expert and Paleontologist, J.G.M. Thewissen, Northeastern Ohio Universities College of Medicine.


Whale Origins


"Pakicetid fossils were important in determining what whales were related to, and they were used to rebuke the idea that whales were closely related to an extinct group of hoofed mammals called mesonychians. These fossils confirmed what was already suggested by scientists studying the DNA of modern whales: that whales’ closest relatives are even-toed ungulates (artiodactyls, such as pig, hippo, camel, deer, and cows). Current research in the Thewissen lab attempts to determine how .. pakicetids locomoted in water and on land."
Source: Origin of Whales, Thewissen Lab Webpage
Read More »

Wentletraps -Angulate vs. Humphrey

0

wentletrap

wentletrap

wentletrap

wentletrap



More Images

Humphrey vs. Angulate?

Gastropod

Auger-Shaped - wentletraps (Epitoniidae)

Angulate Wentletrap Epitonium angulatum (Say)
Description: (1 inch) High, slender, glossy spire. Each whorl with nine to 10 strong ribs, each slightly angled on the whorl shoulder. Smooth spaces between ribs. Round aperture. Operculum. Color: Shiny white interior and exterior. Reddish brown operculum.
Habitat: Occasionally found in drift on ocean beaches.
Range: New York to Uruguay.
Notes: (See brown-band wentletrap Notes) : Also called lined wentletrap. About 24 kinds of wentletraps have been recorded in North Carolina waters. A carnivore, it forages in sand for sea anemones and tears tissue with its jaws. It secretes a substance that turns purple and may anesthetize the anemones. Females lays strings of sand-covered egg capsules. Its young are free-swimming. The precious wentletrap (up to 2 3/4 iches long) from the Pacific Ocean is one of the prettiest shells known.


humphrey wentletrap
Humphrey Wentletrap Images


Humphrey Wentletrap Epitonium humphreysii (Kiener)
Description: (3/4 inch) Small, high-spired shell. Very similar to angulate wentletrap in appearance, habitat and numbers, but eight to nine rounded ribs on each whorl thicker and not angulate at shoulder. Also, generally more slender with a thicker lip on round aperture. Smooth spaces between ribs. Operculum.
Color: White exterior and interior. Mahogany-colored operculum.
Habitat: Occasionally found in drift on ocean beaches.
Range: Massachusetts to Texas.
Notes: (See brown-band wentletrap Notes) : Also called lined wentletrap. About 24 kinds of wentletraps have been recorded in North Carolina waters. A carnivore, it forages in sand for sea anemones and tears tissue with its jaws. It secretes a substance that turns purple and may anesthetize the anemones. Females lays strings of sand-covered egg capsules. Its young are free-swimming. The precious wentletrap (up to 2 3/4 iches long) from the Pacific Ocean is one of the prettiest shells known.
Source: Seashells of North Carolina, North Carolina Sea Grant College Program

Read More »

Common Nutmeg Cancellaria reticulata (Linnaeus)

0
This shell came about from beach-combing,and a lady I met on the beach gave it to me. I've never found a common nutmeg shell before, so I had only one shell to share images of. This shell appears to match the shape, description and image found in the NC Sea Grant Seashell field guide.

common nutmeg
Click for 320 px image
common nutmeg
Click for 320 px image
common nutmeg
Click for 320 px image


More common nutmeg images and further information

Gastropod
Mudsnail-Shaped - nutmegs (Cancellariidae)
Common Nutmeg Cancellaria reticulata (Linnaeus)
Description: (2 1/4 inches) Rough surface on shell. Many spiral cords across many axial ribs, resulting in a lattice or beaded pattern. Elongate aperture with short canal. Inner margin with two strong, thin spiral ridges running into aperture (upper ridge stronger than lower ridge). No operculum.
Color: Banded or splotched with cream and orange or brown.
Habitat: Lives offshore. Occasionally washed onto ocean beaches.
Range: North Carolina to Brazil.
Notes: This species is probably carnivorous because its radula is ideal for feeding on soft-bodied animals.Source: Seashells of North Carolina, North Carolina Sea Grant College Program
Read More »

Dark Variety Lettered Olive

0
I found these lettered olives (Oliva sayana) on the beach today. It was unusual finding an olive this large, but the dark color... love it.

All images posted here

Oliva sayana, lettered olive
Oliva sayana, lettered olive
Oliva sayana, lettered olive



Sally Thomas: Read Orrin Pilkey's How to Read a NC Beach, Chapter 6 pg 113 on the subject of brown and black shells. These are secondary colorations and a result of the reaction of iron to either oxygen (brown or rust of iron oxide) or sulfur (iron sulfide). This may be your answer. Good luck, Sally

Sharon: My dark olives appear to be fading to a lighter color, as they've sat in their box.
Read More »

Alternate Tellin (Say)

0
Sharon: This shell I have is very thin, it's not very wide, the texture is sort of like glass and very shiny.

The closest description I've found in the NC Sea Grant field guide is the Alternate Tellin and the fragile surfclam seems to resemble it also.


alternate tellin
Click for 320 px image

alternate tellin
Click for 320 px image

alternate tellin
Click for 320 px image

alternate tellin
Click for 320 px image

alternate tellin
Click for 320 px image

alternate tellin
Click for 320 px image

alternate tellin
Click for 320 px image

alternate tellin
Click for 320 px image

alternate tellin
Click for 320 px image

alternate tellin
Click for 320 px image

alternate tellin
Click for 320 px image


Hi Sharon,

Yes, this is Tellina alternata Say. I notice that the shell in image 0014 met its demise as a dinner for Polinices duplicatus, whose radula rasped the rather large hole near the umbos.

Regards,
Paul M.

Sharon: From what I'm hearing, this Polinices duplicatus is a real cold blooded killer (they are cold blooded aren't they?) though to be more precise, should I say poikilothermic?

Hi Sharon,

Yes, all the moon snails are very effective predators upon other molluscs, especially bivalves. But sometimes they also attack gastropods, including other moon snails.

Yes, all invertebrates are technically poikilotherms, though the term is most often used in reference to vertebrates (mammals and birds are homeotherms while reptiles, amphibians and fish are poikilotherms).

Regards,
Paul Monfils

Terri: Beautiful tellins, Sharon. And yes, Polinices duplicatus is a real ectothermic killer! Seems there are always shells on the beach with those radula-drilled holes. There are other gastropods who do the same thing (oyster drills, etc.). I've always enjoyed teaching kids to be "beach detectives" -- to see if they could find molluscs that were murdered by other molluscs! A type of beach CSI!

But this discussion reminds me of a Gary Larson cartoon (one of my favorites) with an alligator sitting on the witness stand screaming "Of course I did it in cold blood, you idiot! I'm a reptile!"

Terri K. Hathaway
Marine Education Specialist
North Carolina Sea Grant
http://www.ncseagrant.org/
Read More »

About the Contributors

0
  • Sally Thomas works as a volunteer with the North Carolina Aquariums.

  • Terri Hathaway: I, too, love learning about the natural and life history of marine organisms. They just fascinate me. Guess that's why I went into marine biology (BS degree from UNC Wilmington). I worked as Education Curator at the NC Aquarium on Roanoke Island for 18.5 years before taking this job with NC Sea Grant 2.5 years ago. I now work with teachers across the state, getting marine science into classrooms wherever I can.

  • I'm happy to answer all kinds of questions about the beach, marine life in general or in specific, etc. I just love living near the ocean and being able to see it and walk along it every day. Looking forward to more communcations with you!

    Terri K. Hathaway
    Marine Education Specialist
    North Carolina Sea Grant
    Manteo, NC
    www.ncseagrant.org

    Sharon: Thanks for those verifications/info, Paul.
    Thank you for posting answers on the blog, and I welcome any input, addtl. information -- you can email it to me, and I can publish it into the front pages of the shell entries.

    Very curious.. how have you came to be so knowledgeable on marine biology /
    shell expertee?

    Sharon
  • Paul Monfils: Hi Sharon,

Thanks for your email. I have taken a look at most of the shells you have posted on your website. Most of them are certainly correctly identified. I do have a few comments on a couple of them but don't have much time to write tonight. Just thought I would take a moment to respond to your email. I'll write more about the shells shortly.

I have been a shell collector for almost 50 years, and a specimen shell importer and dealer for over 30 years. My undergraduate degree was in zoology, and I have taught that subject at both high school and college levels (though I now work and teach in the area of medical research).

I'm located in Rhode Island, so several of my local species are the same as yours - Mercenaria mercenaria, Petricola pholadiformis, Ensis directus, Polinices duplicatus, etc. Of course you can also find some of the more southern species that are not found here, and I have quite a few northern species that you don't have locally.

Regards,
Paul Monfils

Sharon: Good morning and thank you for taking the time to respond. That's an impressive resume.

I'm curious, can you please identify this shell for me. I found a couple of these in beachdrift and we haven't any idea which species it is.


snail

snail

snail

snail

snail

snail


Currently Terri K. Hathaway (NC Sea Grant/Marine Biologist) helps to identify and Sally Thomas, a volunteer from the NC Aquariums. May I count you in as a future contributor for shell identification in the future?

This one (above) hasn't been identified or posted.

Thank you, Sharon Mooney

Paul Monfils: Hi Sharon,

You won't find this one in your seashell books because it's a land snail.
I'm not sure what species it is. I don't know land snails as well as I know marine species, but I do have a fair amount of experience with them. I can probably ID it when I have a little more time.

I'll be glad to help with shell ID. I do this frequently for collectors. A couple of collectors, who don't have the capability of photographing shells and posting images online, mail me a box of unidentified shells now and then and enclose return postage. I identify what I can for them and mail them back.

I don't have a webpage of my own. My customers have been asking me for twenty years when I am going to put one up. But shells are only one part of my life. I already have a mailing list of almost 500 collectors, who send me enough orders to keep me busy for most of my available time. I have nearly 5,000 species of wordwide shells in stock. I also sell shells online sometimes, mainly on www.shellauction.net, and occasionally on a few other online auctions. If I put up a website I would have to do shells full time just to keep up, and I really don't want that. Maybe after I retire from my present full time job.

Regards,
Paul Monfils

Sharon: So, Terri Hathaway was correct. Paul Monfils confirms it is a species of land snail.
I wonder what it was doing in beachdrift? I found two of them at separate times, in fact. Maybe a fickle species of snail that never quite left the ocean? -or trying to return. *smile*


I keyed your land snail in The Eastern Land Snails, and confirmed my findings in the Compendium of Landshells and a couple of other sources. Your shell appears to be Triodopsis tridentata (Say), in the family Polygyridae.

Two likely ways for land snails to end up in beach drift -

1. Snail falls into a fresh water stream, is carried to a river which empties into the ocean. (Land snails are usually light weight - without the buoyancy of water around them, they could not carry a heavy shell around as marine snails do - so they typically float.). Once in the ocean it can wash ashore.

2. Snail lives in grassy zone above high tide level. Once the snail dies, wind blows its light weight shell down the beach into the drift line.

I once had a Carrier Shell (Xenophora pallidula) which had attached a land snail shell to itself. That snail shell obviously managed to sink once it reached the ocean, or the Carrier could not have found it.

Regards,
Paul M.
Read More »

Humphrey Wentletrap - Epitonium humphreysii

0
Beautiful wentletraps! I've found only a few of those myself. I treasure them! Definitely look like Humphrey wentletraps to me.

Terri K. Hathaway
Marine Education Specialist
North Carolina Sea Grant
http://www.ncseagrant.org/

wentletrap
Click for 320px image
wentletrap
Click for 320px image
wentletrap
Click for 320px image
wentletrap
Click for 320px image
wentletrap
Click for 320px image
wentletrap
Click for 320px image
wentletrap
Click for 320px image
wentletrap
Click for 320px image
wentletrap
Click for 320px image
wentletrap
Click for 320px image


Humphrey Wentletrap Epitonium humphreysii (Kiener)
Description: (3/4 inch) Small, high-spired shell. Very similar to angulate wentletrap in appearance, habitat and numbers, but eight to nine rounded ribs on each whorl thicker and not angulate at shoulder. Also, generally more slender with a thicker lip on round aperture. Smooth spaces between ribs. Operculum.
Color: White exterior and interior. Mahogany-colored operculum.
Habitat: Occasionally found in drift on ocean beaches.
Range: Massachusetts to Texas.
(See brown-band wentletrap Notes) : Also called lined wentletrap. About 24 kinds of wentletraps have been recorded in North Carolina waters. A carnivore, it forages in sand for sea anemones and tears tissue with its jaws. It secretes a substance that turns purple and may anesthetize the anemones. Females lays strings of sand-covered egg capsules. Its young are free-swimming. The precious wentletrap (up to 2 3/4 iches long) from the Pacific Ocean is one of the prettiest shells known.
Source: Seashells of North Carolina, North Carolina Sea Grant College Program
Read More »

Barnacles, Et Cetera

0
Sharon: I find lots of interesting things on the beach, some of it, I'm not always quite sure what it is...
Sally Thomas: lots of different worm snails, hard corals, barnacles on cockle shell, but I guess you already knew that. I see nothing that resembles an urchin test as suggested, more like a riddles bivalve. Not much help. Sally
Terri: top 9 photos have pieces from what I say are Knorr's (or Florida) worm snails. Or these may be actual worm tubes -- some polychaetes form tubes for protection. Hard to be sure without close examination.

Photos 10-19 are of species of hard coral that live in our waters. These are colonial animals, but do not form reefs.
Photos 10, 11, 18 and 19 are of star coral (Astrangia danae) which grows on hard surfaces, including shells.
Photos 12-17 are of ivory bush coral (Oculina arbuscula) which is a branching coral. Each cup (which I think you're calling a "pod") held one individual animal. These animals belong to the phylum Cnidaria and are related to sea anemones and jellies!

Photo 20 looks like an oyster shell with other oysters shells that have been attached to it.

The crossbarred venus looks like it had some coral settle on it, as well as any oyster and/or another bivalve!

Photo 26 -- interesting piece. It could be several things: a piece of sand dollar/keyhole urchin or a piece of a bivalve that has has boring sponge growing on it (and "drilling" those holes through it).

Photo 27 (from the top) is the cockle with some coral that settled on it.

Photo 28 is part of a test of a sea urchin (an echinoderm).

Photos 29-32 are of a cockle with a barnacle that settled on it.
(remember that barnacles are crustaceans.)

You're finding lots of cool stuff!

Terri K. Hathaway
Marine Education Specialist
North Carolina Sea Grant
http://www.ncseagrant.org/


At first, I thought this was a "ram's horn squid" Spirula spirula but after comparing with the image in the North Carolina Seashells field guide, I'm not sure what this interesting shell is.
barnacles, etc
Click for 320px image
barnacles, etc
Click for 320px image
barnacles, etc
Click for 320px image
barnacles, etc
Click for 320px image
barnacles, etc
Click for 320px image
barnacles, etc
Click for 320px image (At the top of the above photo and below, are two similar shell-like formations, only thinner.)
barnacles, etc
Click for 320px image
barnacles, etc
Click for 320px image
barnacles, etc
Click for 320px image
barnacles, etc
Click for 320px image (close up to one of these pods, see the fine detail inside).

barnacles, etc
Click for 320px image
barnacles, etc
Click for 320px image (a shell cemented to it)
barnacles, etc
Click for 320px image
barnacles, etc
Click for 320px image
barnacles, etc
Click for 320px image (closeup to see the fine detail inside each pod)
barnacles, etc
Click for 320px image
barnacles, etc
Click for 320px image
barnacles, etc
Click for 320px image
barnacles, etc
Click for 320px image

barnacles, etc
Click for 320px image (This was something I found that looks more like a fossil than a shell. It's texture and surface looks more like cement that was shaped inside a shell, and it has some shells stuck inside it (above).
barnacles, etc
Click for 320px image
barnacles, etc
Click for 320px image (This poor crossbarred venus had quite a variety of guests stuck to it).
barnacles, etc
Click for 320px image (Some of the odds and ends I've found on the beach).
barnacles, etc
Click for 320px image (More of that crossbar venus).
barnacles, etc
Click for 320px image
barnacles, etc
Click for 320px image (I find these often on the beach. They are flat and smooth on one side with holes covering the other.)
barnacles, etc
Click for 320px image (Here's a cockleshell with a couple guests stuck to it).
barnacles, etc
Click for 320px image
barnacles, etc
Click for 320px image (Another cockleshell with a guest.)
barnacles, etc
Click for 320px image
barnacles, etc
Click for 320px image
barnacles, etc
Click for 320px image

Read More »

Some Common Coastal NC Species

Alternate Tellin
Alternate Tellin
, Tellina Alternata (Say)

Angelwing
Angelwing
, Cyrtopleura costata (Linnaeus)

Atlantic Auger
Atlantic or Eastern Auger
, Terebra dislocata (Say)

Atlantic calico scallop
Atlantic calico scallop
, Argopecten gibbus (Linnaeus)

Common Nutmeg
Common Nutmeg
, Cancellaria reticulata (Linnaeus)

Cross Barred Venus
Cross Barred Venus
, Chione cancellata (Linnaeus)

Angelwing
Fallen Angelwing
, Atlantic Mud Piddock, Barnea truncata (Say)

Angelwing
False Angelwing
, Petricola pholadiformis (Lamarck)

Humphrey Wentletrap
Humphrey Wentletrap
, Epitonium humphreysii (Kiener)

Imperial Venus Clam
Imperial Venus
, Chione latilirata (Conrad)

Keyhole Limpet
Cayenne keyhole limpet
, Diodora cayenensis (Larmarck)

Keyhole Sand Dollar
Keyhole Sand Dollar
, Mellita quiquiesperforata (Leske, 1778)

Lettered Olive
Lettered Olive
, Oliva sayana (Ravenel)