# Do we know much about sea life during the age of dinosaurs? **URL:** \ **Category:** Factual Questions\ **Created:** [May 3, 2019, 10:54pm UTC](https://boards.straightdope.com/t/do-we-know-much-about-sea-life-during-the-age-of-dinosaurs/833444 "2019-05-03T22:54:57Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Jackknifed\_Juggernaut](https://avatars.discourse-cdn.com/v4/letter/j/9de053/32.png) [@Jackknifed\_Juggernaut](https://boards.straightdope.com/u/Jackknifed_Juggernaut)\ **Post date:** [May 3, 2019, 10:54pm UTC](https://boards.straightdope.com/t/do-we-know-much-about-sea-life-during-the-age-of-dinosaurs/833444/1 "2019-05-03T22:54:57Z")
It seems we have a pretty good picture of what animal life was like during the time of dinosaurs. They dominated the animal kingdom for 150+ million years. They were the king of the jungle when jungle was all there was. But this was on land. As humans that live on land, we place a special importance to what happened on that land. But the earth’s surface is mostly covered with water. Surely, sea life must have its own interesting history. How good of a picture do we have of what transpired below sea level? I assume it’s not as easy to piece together the story, since salt water probably doesn’t preserve things very well. Plus, things tend to move around a lot under water. Finally, it’s probably just way more difficult, technologically, to explore most parts of the oceans. ---
**Author:** ![jayjay](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jayjay/32/6765_2.png) [@jayjay](https://boards.straightdope.com/u/jayjay)\ **Post date:** [May 3, 2019, 11:10pm UTC](https://boards.straightdope.com/t/do-we-know-much-about-sea-life-during-the-age-of-dinosaurs/833444/2 "2019-05-03T23:10:01Z")
The bottoms of oceans don’t STAY at the bottoms of oceans, necessarily. There’s plenty of currently dry land that was once underwater. [Life in Jurassic Oceans](https://www.nhm.ac.uk/discover/life-in-jurassic-oceans.html) [Sea Monsters of the Cretaceous](https://owlcation.com/stem/Sea-Monsters-Monsters-Of-The-Cretaceous) ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [May 4, 2019, 12:25am UTC](https://boards.straightdope.com/t/do-we-know-much-about-sea-life-during-the-age-of-dinosaurs/833444/3 "2019-05-04T00:25:37Z")
There are likely _massively_ more marine and lake fossils available than land fossils. The number of websites I could point you to is enormous, but you could start by looking at [the really horribly designed site](http://oceansofkansas.com/) that compliments the really nice book [_Oceans of Kansas_](https://books.google.com/books/about/Oceans_of_Kansas_Second_Edition.html?id=Ej4rDwAAQBAJ&printsec=frontcover&source=kp_read_button#v=onepage&q&f=false). If your eyes don’t explode when you first look at it, you will find many useful links deep down. There are [icthyosaurs](https://en.wikipedia.org/wiki/Ichthyosaur), [plesiosaurs](https://en.wikipedia.org/wiki/Plesiosauria), [mosasaurs](https://en.wikipedia.org/wiki/Mosasaur), a vast diversity of [cephalopods](https://en.wikipedia.org/wiki/Category:Mesozoic_cephalopods), [fish](https://en.wikipedia.org/wiki/Category:Mesozoic_fish), a [revolution](https://en.wikipedia.org/wiki/Mesozoic_marine_revolution), and most major groups of marine life that are around today were around then. There are places in the world that if you aren’t careful knowledge of mesozoic marine fossils [might enter your head the hard way](https://www.telegraph.co.uk/news/newstopics/howaboutthat/12072425/Fossil-hunters-flock-to-Jurassic-coast-after-cliff-fall.html). Heard of the [White Cliffs of Dover](https://en.wikipedia.org/wiki/White_Cliffs_of_Dover#Geology)? All mesozoic marine fossils. ---
**Author:** ![GreysonCarlisle](https://avatars.discourse-cdn.com/v4/letter/g/a87d85/32.png) [@GreysonCarlisle](https://boards.straightdope.com/u/GreysonCarlisle)\ **Post date:** [May 4, 2019, 12:34am UTC](https://boards.straightdope.com/t/do-we-know-much-about-sea-life-during-the-age-of-dinosaurs/833444/4 "2019-05-04T00:34:09Z")
It IS kinda weird that we can readily find marine fossils on eroded mountain tops. Creationists think that’s evidence of a global flood, but real scientists know better. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [May 4, 2019, 3:04am UTC](https://boards.straightdope.com/t/do-we-know-much-about-sea-life-during-the-age-of-dinosaurs/833444/5 "2019-05-04T03:04:56Z")
For every epoch in the past we know vastly more about sea life than life on land, simply because it is far for animals to fossilize in marine deposits. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [May 4, 2019, 3:14am UTC](https://boards.straightdope.com/t/do-we-know-much-about-sea-life-during-the-age-of-dinosaurs/833444/6 "2019-05-04T03:14:31Z")
> [@Colibri](#): > > For every epoch in the past we know vastly more about sea life than life on land, simply because it is far for animals to fossilize in marine deposits. I think you are missing a word there. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [May 4, 2019, 3:15am UTC](https://boards.straightdope.com/t/do-we-know-much-about-sea-life-during-the-age-of-dinosaurs/833444/7 "2019-05-04T03:15:05Z")
In fact, the modern era of study of fossils largely began with the discovery of ichthyosaurs and plesiosaurs by [Mary\_Anning](https://en.wikipedia.org/wiki/Mary_Anning). These preceded the discovery of dinosaur fossils like Iguanadon by Gideon Mantell in 1822. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [May 4, 2019, 3:16am UTC](https://boards.straightdope.com/t/do-we-know-much-about-sea-life-during-the-age-of-dinosaurs/833444/8 "2019-05-04T03:16:12Z")
> [@Colibri](#): > > For every epoch in the past we know vastly more about sea life than life on land, simply because it is far for animals to fossilize in marine deposits. > [@Darren\_Garrison](#): > > I think you are missing a word there. Yeah, “easier.” ---
**Author:** ![Jackknifed\_Juggernaut](https://avatars.discourse-cdn.com/v4/letter/j/9de053/32.png) [@Jackknifed\_Juggernaut](https://boards.straightdope.com/u/Jackknifed_Juggernaut)\ **Post date:** [May 4, 2019, 12:09pm UTC](https://boards.straightdope.com/t/do-we-know-much-about-sea-life-during-the-age-of-dinosaurs/833444/9 "2019-05-04T12:09:33Z")
Thanks everyone. Had no clue. Are there museums, or major parts of museums, dedicated to underwater fossils? I guess that why I assumed what I did. I’ve been to a few natural history museums in my life, but I think most of the main attractions were land-based. Either that, or I wasn’t paying enough attention. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [May 4, 2019, 2:57pm UTC](https://boards.straightdope.com/t/do-we-know-much-about-sea-life-during-the-age-of-dinosaurs/833444/10 "2019-05-04T14:57:13Z")
> [@Jackknifed\_Juggernaut](#): > > Thanks everyone. Had no clue. Are there museums, or major parts of museums, dedicated to underwater fossils? I guess that why I assumed what I did. I’ve been to a few natural history museums in my life, but I think most of the main attractions were land-based. Either that, or I wasn’t paying enough attention. Most people are more interested in seeing dinosaur fossils than fish or clams. But most large exhibitions will feature a few ichthyosaurs and such. The American Museum of Natural History’s [Hall of Vertebrate Origins](https://www.urbanadvantagenyc.org/wp-content/uploads/2017/12/amnh8.jpg)displays lots of fish, sea turtles, plesiosaurs, ichthyosaurs, etc. (There are also two halls of dinosaurs and one of fossil mammals.) The Smithsonian’s National Museum of Natural History also has a [Hall of Life in Ancient Seas.](https://dinosours.files.wordpress.com/2016/07/dolichorhynchopsclark.jpg) ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [May 4, 2019, 4:34pm UTC](https://boards.straightdope.com/t/do-we-know-much-about-sea-life-during-the-age-of-dinosaurs/833444/11 "2019-05-04T16:34:15Z")
> [@Colibri](#): > > For every epoch in the past we know vastly more about sea life than life on land, simply because it is far for animals to fossilize in marine deposits. To expand on this, to be preserved on land a fossil has to be in a particular environment, one in which sediment is being deposited. This means most fossils will be preserved in places like rivers and swamps. (The Jurassic Morrison Formation, famous for its wealth of dinosaur fossils, was formed in a swampy coastal plain.) Occasional fossils may be preserved by sandstorms or falls of volcanic ash. But at any one time, on the vast majority of the land surface erosion rather than deposition is taking place, so fossils won’t be preserved there. We know virtually nothing about species that lived in mountains or other upland environments. In contrast, in the sea almost nothing but deposition is taking place. There are vast areas where sediment is being deposited where fossils can be preserved. In fact, many marine sediments are composed of almost solid fossils, like the [Gatun Formation](https://pbs.twimg.com/media/DXe2hniV4AAhLKt.jpg) in Panama. It is hundreds of feet thick and extends over many square miles. [This cliff and the ground in the foreground](https://stri.si.edu/sites/default/files/styles/stri-fpp__content-slider/public/fpp/images/275-image5.jpg?itok=XN1HvfMZ) are almost solid shell. (Teeth of the giant shark Megalodon are also relatively common here.) ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [May 4, 2019, 5:11pm UTC](https://boards.straightdope.com/t/do-we-know-much-about-sea-life-during-the-age-of-dinosaurs/833444/12 "2019-05-04T17:11:22Z")
And all of the best preservation sites are water-based. You should browse a few of [these](https://en.wikipedia.org/wiki/Lagerst%C3%A4tte#Important_Konservat-Lagerst%C3%A4tten). (If just one, go with [this](https://burgess-shale.rom.on.ca/en/science/burgess-shale/03-fossils.php) [one](https://burgess-shale.rom.on.ca/en/fossil-gallery/list-species.php). [Or](https://www.sciencenews.org/article/china-fossil-cache-cambrian-explosion) [this](https://theness.com/neurologicablog/index.php/another-massive-cambrian-find/).) ---
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [May 6, 2019, 4:34pm UTC](https://boards.straightdope.com/t/do-we-know-much-about-sea-life-during-the-age-of-dinosaurs/833444/13 "2019-05-06T16:34:34Z")
Dang, late to the party! Teach me to go away for the weekend. Just want to say - marine fossils are the best fossils. Dinosaurs are nice and all, but there’s nothing like the ocean for truly weird shit, from _[Hallucigenia](https://en.wikipedia.org/wiki/Hallucigenia)_ and _[Opabinia](https://en.wikipedia.org/wiki/Opabinia)_ and other Burgess oddities, to [heteromorph ammonites](https://depositsmag.com/2017/03/16/understanding-heteromorph-ammonites/), to [whorl-tooth sharks](https://thumbs-prod.si-cdn.com/WWLK9B0M-GpQcfd9vZA9XEtygnQ=/fit-in/1072x0/https://public-media.si-cdn.com/filer/a6/60/a660c048-0ea3-4c2e-a36b-5414f078459f/misbegotten_helicos_color_x.jpg), to [\*all \*these weird-ass trilobites](https://www.amnh.org/research/paleontology/collections/fossil-invertebrate-collection/trilobite-website/the-trilobite-files/the-strangest-trilobites). ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [May 6, 2019, 8:51pm UTC](https://boards.straightdope.com/t/do-we-know-much-about-sea-life-during-the-age-of-dinosaurs/833444/14 "2019-05-06T20:51:14Z")
Yes, dinosaurs aren’t all that weird compared to ammonites that [repeatedly fold themselves](https://web.archive.org/web/20060920184924/http://homepage.mac.com/nmonks/ammonites/Resources/hmaximus.jpg) or [turn to face the back of their own shell](http://www.geologypage.com/2015/03/scaphites.html) or [crumple themselves into lumps](https://paleopetshop.files.wordpress.com/2018/05/nipponites.jpg). Imagine how much their balance and movement had to change, multiple times in their lives, and for what reason? _How_ did they move, and feed? ---
**Author:** ![nightshadea](https://avatars.discourse-cdn.com/v4/letter/n/7ba0ec/32.png) [@nightshadea](https://boards.straightdope.com/u/nightshadea)\ **Post date:** [May 6, 2019, 9:10pm UTC](https://boards.straightdope.com/t/do-we-know-much-about-sea-life-during-the-age-of-dinosaurs/833444/15 "2019-05-06T21:10:22Z")
ee before mankind even existed there was an omnipotent power on the earth that had land air and sea travel mastered …… that helped foster peace and understanding throughout the world and had advanced sciences and even worldwide sport that wouldn’t be discovered for millions of years They had such concepts as conservation interspecies peace and harmony we cant even get back to today Sadly their greatest invention was lost because their astronomy hadn’t advanced enough to catch the big rock that would doom them all …. The time tunnel! Even though it took millions of years for humans to understand their ruins and notes when the ancients finally figured it out… it took us out of the mud and caves and started us on a path of enlightenment It was the trolodons and the benevolent and omnipotent dinosaur train industries! I mean it makes more sense that the worlds smartest beings until the human race formed all of this before we even existed and all the ancients did was evolve until their intelligence could comprehend such advanced learning…:D:p ---
**Author:** ![bump](https://avatars.discourse-cdn.com/v4/letter/b/7c8e57/32.png) [@bump](https://boards.straightdope.com/u/bump)\ **Post date:** [May 6, 2019, 9:28pm UTC](https://boards.straightdope.com/t/do-we-know-much-about-sea-life-during-the-age-of-dinosaurs/833444/16 "2019-05-06T21:28:45Z")
Not only do we know a lot about Mesozoic Era (250-65 million years ago) ocean life, we know a lot about ocean live stretching as far back as 540 million years ago in the Cambrian era. Whole classes of extinct creatures like trilobites and strange ones like sea scorpions (cousins to arachnids) came and went prior to the dinosaurs. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [May 7, 2019, 11:42am UTC](https://boards.straightdope.com/t/do-we-know-much-about-sea-life-during-the-age-of-dinosaurs/833444/17 "2019-05-07T11:42:52Z")
> [@Jackknifed\_Juggernaut](#): > > Thanks everyone. Had no clue. Are there museums, or major parts of museums, dedicated to underwater fossils? I guess that why I assumed what I did. I’ve been to a few natural history museums in my life, but I think most of the main attractions were land-based. Either that, or I wasn’t paying enough attention. No offense, but I think you weren’t paying enough attention. Museum halls are filled with fossils of ammonites (those coiled shell octopus things; the only surviving relatives are the chambered and paper nautilus) and trilobites, both of which went extinct with the dinosaurs, along with crinoids (sea lilies), which were much more abundant then. When I was a kid, fossil hunting, the primary fossils were sea life, such as shells (brachiopods and pelycpods), crinoids, bryozoans, and (further afield) fossil fish. My “handbook” was the Golden Nature Guide to Fossils, which listed a lot of these, along with trilobites, ammonites, and other sea life far more prominently than dinosaurs and other megafauna. > **[Fossils: A Guide to Prehistoric Life (A... book by Herbert S. Zim](https://www.thriftbooks.com/w/fossils-a-guide-to-prehistoric-life-a-golden-nature-guide_herbert-s-zim_frank-ht-rhodes/391019/#isbn=1582381429&idiq=4724882)** > > Buy a cheap copy of Fossils: A Guide to Prehistoric Life (A... book by Herbert S. Zim. Golden has one of the most authoritative and largest selections of nature guide available. Perfect for nature lovers of all ages, this guide to fossils is a...... > **[golden nature guide fossils - Bing](https://www.bing.com/images/search?q=golden%2Bnature%2Bguide%2Bfossils&FORM=HDRSC2)** > > Intelligent search from Bing makes it easier to quickly find what you’re looking for and rewards you. Of course, dinosaurs are sexy, so they get a lot of “play”, but another type of fossil that is incredibly common, yet overlooked (and, I think, underrepresented in museum halls) are the plants. Lotsa plant fossils out there. ---
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [May 7, 2019, 3:16pm UTC](https://boards.straightdope.com/t/do-we-know-much-about-sea-life-during-the-age-of-dinosaurs/833444/18 "2019-05-07T15:16:31Z")
> [@CalMeacham](#): > > No offense, but I think you weren’t paying enough attention. Museum halls are filled with fossils of ammonites (those coiled shell octopus things; the only surviving relatives are the chambered and paper nautilus) Slight nitpick - ammonites were actually more closly related to the _shell-less_ or _internal-shelled_ coleoids - octopuses, squid and cuttlefish - this includes the extinct internally-shelled [belemnites](https://en.wikipedia.org/wiki/Belemnitida)and the _Argonauta_ (the aforementioned [paper nautilus](https://en.wikipedia.org/wiki/Argonaut_(animal)) - but be aware that’s \*not \*a shell, it’s an egg case. The actual animal is a kind of octopus) than shelled nautiloids like _[Nautilus pompilius](https://en.wikipedia.org/wiki/Chambered_nautilus)_ (the chambered nautilus). The confusion is doubtless compounded by there being plenty of fossil nautiloids too. But they’re relatively easy to tell apart in most specimens. ---
**Author:** ![TSBG](https://avatars.discourse-cdn.com/v4/letter/t/77aa72/32.png) [@TSBG](https://boards.straightdope.com/u/TSBG)\ **Post date:** [May 7, 2019, 6:10pm UTC](https://boards.straightdope.com/t/do-we-know-much-about-sea-life-during-the-age-of-dinosaurs/833444/19 "2019-05-07T18:10:26Z")
The LA Museum of Natural History redid their dinosaur section a few years ago. Big section on dinosaurs’ watery cousins. My daughter wasn’t interested. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [May 7, 2019, 6:58pm UTC](https://boards.straightdope.com/t/do-we-know-much-about-sea-life-during-the-age-of-dinosaurs/833444/20 "2019-05-07T18:58:32Z")
> [@CalMeacham](#): > > and trilobites, both of which went extinct with the dinosaurs, along with crinoids (sea lilies), which were much more abundant then. Another slight nitpick–the last of the trilobites died before the first of the dinosaurs appeared–they were in serious decline by the Permian and the last of them died off in The Big One. [Next page](https://boards.straightdope.com/t/do-we-know-much-about-sea-life-during-the-age-of-dinosaurs/833444.md?page=2)