# Were any of the large prehistoric marine reptiles venomous? **URL:** \ **Category:** Factual Questions\ **Created:** [September 10, 2021, 7:14pm UTC](https://boards.straightdope.com/t/were-any-of-the-large-prehistoric-marine-reptiles-venomous/950479 "2021-09-10T19:14:02Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![GreysonCarlisle](https://avatars.discourse-cdn.com/v4/letter/g/a87d85/32.png) [@GreysonCarlisle](https://boards.straightdope.com/u/GreysonCarlisle)\ **Post date:** [September 10, 2021, 7:14pm UTC](https://boards.straightdope.com/t/were-any-of-the-large-prehistoric-marine-reptiles-venomous/950479/1 "2021-09-10T19:14:02Z")
I was reading about the mosasaurs, and there seems to be some debate on whether they were most closely related to Komodo dragons or to snakes. So I started wondering whether the mosasaurs could have had some sort of toxic bite. They were pretty big, so I can’t see that venom would have helped them much in hunting. But there were lots of other big things around, too, so they may have used it for defense. Do we know (or suspect) anything about that, like did some of the larger marine reptiles from that time have hollow fangs or grooved teeth or anything else that might suggest that they were venomous? ---
**Author:** ![md-2000](https://avatars.discourse-cdn.com/v4/letter/m/9d8465/32.png) [@md-2000](https://boards.straightdope.com/u/md-2000)\ **Post date:** [September 10, 2021, 8:38pm UTC](https://boards.straightdope.com/t/were-any-of-the-large-prehistoric-marine-reptiles-venomous/950479/2 "2021-09-10T20:38:22Z")
Are there any large animals (then or now) that are venomous? It seems to me the biggest they get is the stingray or jellyfish (which are not too mobile). AFAIK these tend to be more defensive, not for hunting. ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [September 10, 2021, 8:57pm UTC](https://boards.straightdope.com/t/were-any-of-the-large-prehistoric-marine-reptiles-venomous/950479/3 "2021-09-10T20:57:25Z")
I have always wondered why more mammals did not evolve venom. The platypus and the echidna are the only two that I know of and they use it purely for defense. It might create a mammal that is too successful and quickly wipes out his food source. ---
**Author:** ![AHunter3](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ahunter3/32/368_2.png) [@AHunter3](https://boards.straightdope.com/u/AHunter3)\ **Post date:** [September 10, 2021, 9:58pm UTC](https://boards.straightdope.com/t/were-any-of-the-large-prehistoric-marine-reptiles-venomous/950479/4 "2021-09-10T21:58:05Z")
> [@md-2000](#): > > Are there any large animals (then or now) that are venomous? Gila monsters reach pretty decent size, as do the above-mentioned komodo dragons. ---
**Author:** ![What\_Exit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/what_exit/32/10652_2.png) [@What\_Exit](https://boards.straightdope.com/u/What_Exit)\ **Post date:** [September 10, 2021, 10:18pm UTC](https://boards.straightdope.com/t/were-any-of-the-large-prehistoric-marine-reptiles-venomous/950479/5 "2021-09-10T22:18:40Z")
There are more venomous mammals. Even a few primates. I present the Slow Loris. > **[Slow loris](https://en.wikipedia.org/wiki/Slow_loris#Venom)** > > Pages for logged out editors learn more > > > > Slow lorises are a group of several species of nocturnal strepsirrhine primates that make up the genus Nycticebus. Found in Southeast Asia and bordering areas, they range from Bangladesh and Northeast India in the west to the Sulu Archipelago in the Philippines in the east, and from Yunnan province in China in the north to the island of Java in the south. Although many previous classifications recognized as few as a single all-inclusive species... The Komodo is the largest land based animal with venom. I don’t believe the fossil record would show if mosasaurs were venomous or not. ---
**Author:** ![Pleonast](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pleonast/32/1183_2.png) [@Pleonast](https://boards.straightdope.com/u/Pleonast)\ **Post date:** [September 10, 2021, 10:24pm UTC](https://boards.straightdope.com/t/were-any-of-the-large-prehistoric-marine-reptiles-venomous/950479/6 "2021-09-10T22:24:03Z")
Mosasaurs are part of the assumed clade [Toxicofera](https://en.m.wikipedia.org/wiki/Toxicofera), which has venom as a feature. So, it’s quite possible they did have venom, but unlikely to have the advanced toxins and delivery systems that some snakes have. > **[Toxicofera](https://en.m.wikipedia.org/wiki/Toxicofera)** > > Pages for logged out editors learn more > > > Toxicofera (Greek for "those who bear toxins") is a proposed clade of scaled reptiles (squamates) that includes the Serpentes (snakes), Anguimorpha (monitor lizards, gila monster, and alligator lizards) and Iguania (iguanas, agamas, and chameleons). Toxicofera contains about 4,600 species, (nearly 60%) of extant Squamata. It encompasses all venomous reptile species, as well as numerous related non-venomous species. There is little morphological ... ---
**Author:** ![GreysonCarlisle](https://avatars.discourse-cdn.com/v4/letter/g/a87d85/32.png) [@GreysonCarlisle](https://boards.straightdope.com/u/GreysonCarlisle)\ **Post date:** [September 10, 2021, 10:31pm UTC](https://boards.straightdope.com/t/were-any-of-the-large-prehistoric-marine-reptiles-venomous/950479/7 "2021-09-10T22:31:13Z")
> [@HoneyBadgerDC](#): > > I have always wondered why more mammals did not evolve venom. These [cute lil guys](https://en.wikipedia.org/wiki/Solenodon), too. And their extinct North American [cousin](https://en.wikipedia.org/wiki/Bisonalveus). ---
**Author:** ![GreysonCarlisle](https://avatars.discourse-cdn.com/v4/letter/g/a87d85/32.png) [@GreysonCarlisle](https://boards.straightdope.com/u/GreysonCarlisle)\ **Post date:** [September 10, 2021, 10:33pm UTC](https://boards.straightdope.com/t/were-any-of-the-large-prehistoric-marine-reptiles-venomous/950479/8 "2021-09-10T22:33:55Z")
> [@Pleonast](#): > > Mosasaurs are part of the assumed clade [Toxicofera](https://en.m.wikipedia.org/wiki/Toxicofera), which has venom as a feature. So, it’s quite possible they did have venom, but unlikely to have the advanced toxins and delivery systems that some snakes have. > > [Toxicofera - Wikipedia](https://en.m.wikipedia.org/wiki/Toxicofera) Nice find! > [@the article](#): > > We even isolated from a rat snake _Coelognathus radiatus_ (formerly known as Elaphe radiata), a snake common in pet stores, a typical cobra-style neurotoxin, one that is as potent as comparative toxins found in close relatives of the cobra. I’ve always been creeped out by snakes. Maybe this is why. ---
**Author:** ![Melbourne](https://avatars.discourse-cdn.com/v4/letter/m/b5e925/32.png) [@Melbourne](https://boards.straightdope.com/u/Melbourne)\ **Post date:** [September 11, 2021, 12:09am UTC](https://boards.straightdope.com/t/were-any-of-the-large-prehistoric-marine-reptiles-venomous/950479/9 "2021-09-11T00:09:37Z")
> [@HoneyBadgerDC](#): > > The platypus and the echidna are the only two that I know of and they use it purely for defense And mammals by courtesy and definition. They are also the only two egg-laying mammals. Research suggests that the echidna evolved from an animal with toxic spurs, but the spurs aren’t poisonous now. On modern echidnas, it’s used for marking, like what a cat or dog does. On modern platypuses, the gene is called a ‘defensin’ gene, for ‘defense’ against microbial infection, but the spur is apparently mainly used for mating competition. ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [September 17, 2021, 5:24pm UTC](https://boards.straightdope.com/t/were-any-of-the-large-prehistoric-marine-reptiles-venomous/950479/10 "2021-09-17T17:24:53Z")
> [@GreysonCarlisle](#): > > > [@the article](#): > > > > We even isolated from a rat snake _Coelognathus radiatus_ (formerly known as Elaphe radiata), a snake common in pet stores, a typical cobra-style neurotoxin, one that is as potent as comparative toxins found in close relatives of the cobra. Oh, great. At least I feel a little better about dispatching the rat snake that slithered into my garage, not only refusing to leave when encouraged to do so, but rearing and lunging at me as well.