# What was the biggest "pre-dinosaur" animal? **URL:** \ **Category:** Factual Questions\ **Created:** [February 26, 2013, 8:41pm UTC](https://boards.straightdope.com/t/what-was-the-biggest-pre-dinosaur-animal/651466 "2013-02-26T20:41:00Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![gytalf2000](https://avatars.discourse-cdn.com/v4/letter/g/ac91a4/32.png) [@gytalf2000](https://boards.straightdope.com/u/gytalf2000)\ **Post date:** [February 26, 2013, 8:41pm UTC](https://boards.straightdope.com/t/what-was-the-biggest-pre-dinosaur-animal/651466/1 "2013-02-26T20:41:00Z")
I know that the big sauropod dinosaurs were the biggest land animals ever. (The blue whale exceeds the mass of the largest dinosaur, but it doesn’t have to support its weight, of course…) My question is, what was the biggest animal from the time before the dinosaurs? Both terrestrial and aquatic creatures can be included. Thanks in advance for any information that you can provide. ---
**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:** [February 26, 2013, 8:47pm UTC](https://boards.straightdope.com/t/what-was-the-biggest-pre-dinosaur-animal/651466/2 "2013-02-26T20:47:55Z")
My first thoughts were **Eurypterids** (Sea Scorpions) in the water – they got to be 2 meters in length > **[Eurypterid](https://en.wikipedia.org/wiki/Eurypterid)** > > Eurypterids, often informally called sea scorpions, are a group of extinct arthropods that form the order Eurypterida. The earliest known eurypterids date to the Darriwilian stage of the Ordovician period 467.3 million years ago. The group is likely to have appeared first either during the Early Ordovician or Late Cambrian period. With approximately 250 species, the Eurypterida is the most diverse Paleozoic chelicerate order. Following their appearance during the Ordovician, eurypterids became... And **Eryops** , an amphibian, on land. They grew to 1.5-2 meters > **[Eryops](https://en.wikipedia.org/wiki/Eryops)** > > Eryops (/ˈɛri.ɒps/; from Greek ἐρύειν, eryein, 'drawn-out' + ὤψ, ops, 'face', because most of its skull was in front of its eyes) is a genus of extinct, amphibious temnospondyls. It contains the single species Eryops megacephalus, the fossils of which are found mainly in early Permian (about 295 million years ago) rocks of the Texas Red Beds, located in Archer County, Texas. Fossils have also been found in late Carboniferous period rocks from New Mexico. Several complete skeletons of Eryops hav... **Moschops** a _therapsid_ (sorta proto-mammals) grew to be over 5 meters, and were the largest things in the Permian (the geologic period just before the Mesozoic era, the Age of the Dinosaurs): > **[Moschops](https://en.wikipedia.org/wiki/Moschops)** > > Moschops (Greek for "calf face") is an extinct genus of therapsids that lived in the Guadalupian epoch, around 265–260 million years ago. They were heavily built plant eaters, and they may have lived partly in water, as hippopotamuses do. They had short, thick heads and might have competed by head-butting each other. Their elbow joints allowed them to walk with a more mammal-like gait rather than crawling. Their remains were found in the Karoo region of South Africa, belonging to the Tapinoceph... These are the biggest I can think of, off the top of my head. I wouldn’t be surprised if something bigger was around, though. ---
**Author:** ![Asympotically\_fat](https://avatars.discourse-cdn.com/v4/letter/a/e47c2d/32.png) [@Asympotically\_fat](https://boards.straightdope.com/u/Asympotically_fat)\ **Post date:** [February 26, 2013, 8:49pm UTC](https://boards.straightdope.com/t/what-was-the-biggest-pre-dinosaur-animal/651466/3 "2013-02-26T20:49:11Z")
I believe just before the dinosaurs certain synapsids (a clade that later gave rise to the mammals) were the dominant large land animals. ---
**Author:** ![gytalf2000](https://avatars.discourse-cdn.com/v4/letter/g/ac91a4/32.png) [@gytalf2000](https://boards.straightdope.com/u/gytalf2000)\ **Post date:** [February 26, 2013, 8:51pm UTC](https://boards.straightdope.com/t/what-was-the-biggest-pre-dinosaur-animal/651466/4 "2013-02-26T20:51:47Z")
> [@CalMeacham](#): > > My first thoughts were **Eurypterids** (Sea Scorpions) in the water – they got to be 2 meters in length > > [Eurypterid - Wikipedia](http://en.wikipedia.org/wiki/Eurypterid) > > And **Eryops** , an amphibian, on land. They grew to 1.5-2 meters > > [Eryops - Wikipedia](http://en.wikipedia.org/wiki/Eryops) > > These are the biggest I can think of, off the top of my heasd. I wouldn’t be surprised if something bigger was around, though. Nifty! Thanks. I love prehistoric animals. When I was much younger, I would read dinosaur books all the time. There have been a whole lot more discoveries in the ensuing years, though, and it is hard to keep up. Plus, my memory is not always so good… ---
**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:** [February 26, 2013, 8:59pm UTC](https://boards.straightdope.com/t/what-was-the-biggest-pre-dinosaur-animal/651466/5 "2013-02-26T20:59:57Z")
Well, these are all from my memories of prehistoric animal books (and museum visits) from my youth, some 50 years ago\*, so there may have been new discoveries that I haven’t heard of. But Wikipedia says Moschops still hols the Permian record. \*depressing (to me) but true. ---
**Author:** ![The\_Peyote\_Coyote](https://avatars.discourse-cdn.com/v4/letter/t/5f8ce5/32.png) [@The\_Peyote\_Coyote](https://boards.straightdope.com/u/The_Peyote_Coyote)\ **Post date:** [February 26, 2013, 9:37pm UTC](https://boards.straightdope.com/t/what-was-the-biggest-pre-dinosaur-animal/651466/6 "2013-02-26T21:37:48Z")
I would suggest prionsuchus, a 30-foot long amphibian that was an ambush predator. It’s the largest amphibian known to science and pretty cool. It lived in the Triassic. ---
**Author:** ![The\_Peyote\_Coyote](https://avatars.discourse-cdn.com/v4/letter/t/5f8ce5/32.png) [@The\_Peyote\_Coyote](https://boards.straightdope.com/u/The_Peyote_Coyote)\ **Post date:** [February 26, 2013, 9:43pm UTC](https://boards.straightdope.com/t/what-was-the-biggest-pre-dinosaur-animal/651466/7 "2013-02-26T21:43:37Z")
Whoops, excuse me, i meant the Permian Era. ---
**Author:** ![HubZilla](https://avatars.discourse-cdn.com/v4/letter/h/ccd318/32.png) [@HubZilla](https://boards.straightdope.com/u/HubZilla)\ **Post date:** [February 26, 2013, 9:51pm UTC](https://boards.straightdope.com/t/what-was-the-biggest-pre-dinosaur-animal/651466/8 "2013-02-26T21:51:20Z")
What about a Dimetrodon? I hear tell they are not dinosaurs. Why is that, simply because they were pre-Triassic? They look like dinosaurs to me, and they were in my 80s plastic dinosaur sets (same size as plastic army men). ---
**Author:** ![Earl\_Snake-Hips\_Tucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/earl_snake-hips_tucker/32/3269_2.png) [@Earl\_Snake-Hips\_Tucker](https://boards.straightdope.com/u/Earl_Snake-Hips_Tucker)\ **Post date:** [February 26, 2013, 10:03pm UTC](https://boards.straightdope.com/t/what-was-the-biggest-pre-dinosaur-animal/651466/9 "2013-02-26T22:03:15Z")
Well, sorta. There’s the strict definition, and the common definition. For the ‘true’ dinosaurs,they [can be defined as the last common ancestor of birds (Saurischia) and Triceratops (Ornithischia) and all the descendants of that ancestor. With that definition, the pterosaurs and several species of archosaurs narrowly miss out on being classified as dinosaurs.](http://en.wikipedia.org/wiki/Evolution_of_dinosaurs) So our distant sailback cousin is just a little too far back. The [common (non-scientific) definition](http://www.merriam-webster.com/dictionary/dinosaur) includes any large prehistoric reptiles. ---
**Author:** ![cjepson](https://avatars.discourse-cdn.com/v4/letter/c/a9adbd/32.png) [@cjepson](https://boards.straightdope.com/u/cjepson)\ **Post date:** [February 26, 2013, 10:29pm UTC](https://boards.straightdope.com/t/what-was-the-biggest-pre-dinosaur-animal/651466/10 "2013-02-26T22:29:51Z")
Another candidate: [_Dunkleosteus_.](http://en.wikipedia.org/wiki/Dunkleosteus) Late Devonian, up to 10 meters, and 4 short tons, according to the article. A relative of _Dinichthys_, which was also giant but little is known about it. ---
**Author:** ![Polycarp](https://avatars.discourse-cdn.com/v4/letter/p/82dd89/32.png) [@Polycarp](https://boards.straightdope.com/u/Polycarp)\ **Post date:** [February 26, 2013, 10:33pm UTC](https://boards.straightdope.com/t/what-was-the-biggest-pre-dinosaur-animal/651466/11 "2013-02-26T22:33:43Z")
Contemporary with the earliest dinosaurs (Upper Triassic) was Shonisaurus, an ichthyosaur. A [Wikipedia table of ichthyosaur genera](http://en.wikipedia.org/wiki/List_of_ichthyosaurs) says this in its notes: > [@](#): > > The largest genus of ichthyosaur that has yet been found. Fossils of Shonisaurus were first found in Nevada in 1920. It lived during the Norian stage of the late Triassic period and had a long pointed mouth that contained teeth only at the front end. S. popularis specimens reached a length of 15 meters (50 feet). A second species, S. sikanniensis, was later discovered in British Columbia and has an estimated length of 21 meters (70 feet). ---
**Author:** ![gytalf2000](https://avatars.discourse-cdn.com/v4/letter/g/ac91a4/32.png) [@gytalf2000](https://boards.straightdope.com/u/gytalf2000)\ **Post date:** [February 26, 2013, 10:50pm UTC](https://boards.straightdope.com/t/what-was-the-biggest-pre-dinosaur-animal/651466/12 "2013-02-26T22:50:46Z")
> [@Polycarp](#): > > Contemporary with the earliest dinosaurs (Upper Triassic) was Shonisaurus, an ichthyosaur. A [Wikipedia table of ichthyosaur genera](http://en.wikipedia.org/wiki/List_of_ichthyosaurs) says this in its notes: Wow! Very impressive. ---
**Author:** ![the\_diego](https://avatars.discourse-cdn.com/v4/letter/t/7bcc69/32.png) [@the\_diego](https://boards.straightdope.com/u/the_diego)\ **Post date:** [February 26, 2013, 11:22pm UTC](https://boards.straightdope.com/t/what-was-the-biggest-pre-dinosaur-animal/651466/13 "2013-02-26T23:22:31Z")
I would think crocodiles that came before the dinos easily exceeded 25 feet in length, maybe a lot more. ---
**Author:** ![The\_Peyote\_Coyote](https://avatars.discourse-cdn.com/v4/letter/t/5f8ce5/32.png) [@The\_Peyote\_Coyote](https://boards.straightdope.com/u/The_Peyote_Coyote)\ **Post date:** [February 27, 2013, 12:54am UTC](https://boards.straightdope.com/t/what-was-the-biggest-pre-dinosaur-animal/651466/14 "2013-02-27T00:54:38Z")
Not disputing the coolness of Shonisaurus, but it wouldn’t be disqualified because it was in the Triassic? I thought the OP wanted creatures from before the time of dinosaurs. ---
**Author:** ![septimus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/septimus/32/410_2.png) [@septimus](https://boards.straightdope.com/u/septimus)\ **Post date:** [February 27, 2013, 1:28am UTC](https://boards.straightdope.com/t/what-was-the-biggest-pre-dinosaur-animal/651466/15 "2013-02-27T01:28:02Z")
Giant Millipede. [QUOTE=Wikipedia] In the Upper Carboniferous (340 to 280 million years ago), Arthropleura became the largest known land invertebrate of all time, reaching lengths of up to 2.6 metres (8 ft 6 in). … Arthropleura became extinct at the start of the Permian period, when the moist climate began drying out, destroying the rainforests of the Carboniferous, and allowing the desertification characteristic of the Permian. Because of this, oxygen levels in the atmosphere began to decline to more modest levels. None of the giant arthropods (except for the giant dragonflies such as Meganeuropsis, which continued thriving throughout the Permian) could survive the new dry, lower-oxygen climate. [/QUOTE] ---
**Author:** ![heathen\_earthling](https://avatars.discourse-cdn.com/v4/letter/h/13edae/32.png) [@heathen\_earthling](https://boards.straightdope.com/u/heathen_earthling)\ **Post date:** [February 27, 2013, 3:22am UTC](https://boards.straightdope.com/t/what-was-the-biggest-pre-dinosaur-animal/651466/16 "2013-02-27T03:22:04Z")
It doesn’t beat everything already mentioned, but still cool: [_Rhizhodus hibberti_](http://old.sinodino.cc/data/uploadfile/200606/20060603161721946.jpg), a 7-metre-long Paleozoic lungfish relative, and possibly the biggest freshwater fish ever. ---
**Author:** ![Polycarp](https://avatars.discourse-cdn.com/v4/letter/p/82dd89/32.png) [@Polycarp](https://boards.straightdope.com/u/Polycarp)\ **Post date:** [February 27, 2013, 12:00pm UTC](https://boards.straightdope.com/t/what-was-the-biggest-pre-dinosaur-animal/651466/17 "2013-02-27T12:00:27Z")
> [@the\_diego](#): > > I would think crocodiles that came before the dinos easily exceeded 25 feet in length, maybe a lot more. Good call, and I did a little research. The Crurotarsi, which include the Crocodilia, the closely-related Phytosaurs and Aetosaurs, and a few odds and ends, all date from the Late Triassic, and apparently the big 35-foot forms were contemporary with the heydey of the dinosaurs, not something preceding them. (Counterintuitive fact: crocs are the closest living relatives of birds.) > [@The\_Peyote\_Coyote](#): > > Not disputing the coolness of Shonisaurus, but it wouldn’t be disqualified because it was in the Triassic? I thought the OP wanted creatures from before the time of dinosaurs. I’ll leave it to the OP to make a call here. The “time of the dinosaurs” was the last epoch of the Triassic Period, when they got their start and rapidly radiated, then the following Jurassic and Cretaceous Periods, when most of the spectacular dinosaurs flourished. I’d maintain that “contemporary with when they were just getting their start” is “before them,” but can see why others might disagree. ---
**Author:** ![cjepson](https://avatars.discourse-cdn.com/v4/letter/c/a9adbd/32.png) [@cjepson](https://boards.straightdope.com/u/cjepson)\ **Post date:** [February 27, 2013, 2:35pm UTC](https://boards.straightdope.com/t/what-was-the-biggest-pre-dinosaur-animal/651466/18 "2013-02-27T14:35:01Z")
Certainly not the biggest, but perhaps the longest pre-dinosaur animal was a species of crinoid (sea lily) that had a stalk up to 40m (130 ft) in length. ---
**Author:** ![gytalf2000](https://avatars.discourse-cdn.com/v4/letter/g/ac91a4/32.png) [@gytalf2000](https://boards.straightdope.com/u/gytalf2000)\ **Post date:** [February 27, 2013, 3:01pm UTC](https://boards.straightdope.com/t/what-was-the-biggest-pre-dinosaur-animal/651466/19 "2013-02-27T15:01:21Z")
> [@The\_Peyote\_Coyote](#): > > Not disputing the coolness of Shonisaurus, but it wouldn’t be disqualified because it was in the Triassic? I thought the OP wanted creatures from before the time of dinosaurs. Well, before the dinosaurs, or while they were still one of many groups of creatures struggling for dominance. I know that they shared the planet with several other types of reptiles and creatures for a while before they became the “reigning reptiles” in the late Triassic until the meteor hit at the end of the Cretaceous. (I just don’t remember a lot of the details.) ---
**Author:** ![JKellyMap](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jkellymap/32/15880_2.png) [@JKellyMap](https://boards.straightdope.com/u/JKellyMap)\ **Post date:** [February 27, 2013, 3:16pm UTC](https://boards.straightdope.com/t/what-was-the-biggest-pre-dinosaur-animal/651466/20 "2013-02-27T15:16:20Z")
> [@CalMeacham](#): > > My first thoughts were **Eurypterids** (Sea Scorpions) in the water – they got to be 2 meters in length > > [Eurypterid - Wikipedia](http://en.wikipedia.org/wiki/Eurypterid)… Mmmm, them’s good eatin’! _“Red Eurypterid, for the seafood lover in you…”_ Neat post, and well done remembering. Also others’ posts on _Rhizodus_, and on _Dunkleosteus_. I actually wrote a fifth-grade essay on the latter. Not 50 years ago, but close enough. [Next page](https://boards.straightdope.com/t/what-was-the-biggest-pre-dinosaur-animal/651466.md?page=2)