Ocean Reptiles ?

[Shiloh]

I think he's following a 'parallel evolution' idea, at least while fishing for species to base his game creatures from, anyway.

Exactly.

One of the players knows a lot more about biology than I do, so I prefer
to stay close to real world (= obviously "working") body plans in order
to avoid being caught with a design that would obviously be impossible.

Of course, I do add "alien" features to the "real world models", but the
basic creature is one I know to exist (or have existed - I often use ra-
ther strange prehistoric animals, like those of the Ediacara or Burgess
Shale fauna).

While not stricly "reptiles", the icthyosaurs from Earth's past seem pretty much (from their body plans) to have been entirely aquatic. Don't know whether we know how they gave birth, but there's no real reason why an alien evolution of scalybeasts wouldn't have gone down the line of live birth, bypassing or evolving "past" the whole (what we commonly think of as an) "egg" thing.

 

[alex_greene]

Deep down, it's all maths.

Of course, your ocean-dwelling reptiles don't have the limitations of land-based reptilians, so your saltwater viviparous crocodile analogue could grow to a terrifying size.

Look at the extinct saurian Liopleurodon - a twenty metre monster.

 

[Gaidheal]

I knew I'd be trumped by a cocky mathematician sooner or later. ;¬)

 

[rust]

Thank you very much to all of you, this thread has given me a lot of
new ideas to work with (= torture the players with).

 

[Bygoneyrs]

You know there was a TV serious back 1-2 years ago that only was on One Season, but it was about a creature that had been genetically created and lived in the oceans. It laid a kinda egg, and hatched and grew to larger than a blue whale in size and ate EVERYTHING!!! They were intelligent and nasty. They caused all sorts of problems.

My only comment would be to tone them down and make them no bigger than say 12 feet long max. Maybe make a few other shark like critters as their enemies to keep them in check. BTW they could walk out of the water and walk on land on all fours. They also had a kinda of electrical discharge as a weapon that they used most effectively too.

Penn

 

[rust]

Thank you very much, I have put the idea on my list.

Right now the most nasty animal on Anuira is a cousin of the
Dunkleosteus:
http://en.wikipedia.org/wiki/Dunkleosteus

However, with 571 million square kilometers, the planet is big
enough to provide surprises for the characters for a long time
- even truly big surprises. :twisted:

 

[Rikki Tikki Traveller]

I knew I'd be trumped by a cocky mathematician sooner or later. ;¬)

Scientists THINK

Engineers DO

:twisted:

 

[rust]

Over here they say that each scientist should keep an engineer or two
so he has someone to do the actual work ... :wink:

 

[Myrm]

There ar e anumber of marine reptiles - the Sea snake example already given is the most extreme but there are a variety of options Extant and Extinct.

http://en.wikipedia.org/wiki/List_of_marine_reptiles

Suffice it to say, reptiles can exist in a marine environment. If by purely marine you mean 'no land on the planet' than you might raise some questions from your biologist due to the fact that most of the reptilian featured evolved as part of the original colonisation of land by said reptiles and the marine ones have simply gone back to the sea.

Never having come out at all in the evolutionary past would make it less likely that the repltilian adaptations occured in the first place. You might need to do some background planetology to explain why replites evoled in the first place and now have to live in the water....a cataclysmic deluge story, a few rare bits of land or a volcanic history that is extreme you might get away with if their earth sciences are weaker than their biology.

 

[rust]

Thank you very much, a very good point.

Right now my map of the water world Anuira has three "plateaus" the
size of small continents, in an average depth of about 200 meters.

I am not sure whether a major ice age could be severe enough to ma-
ke a sinking of the sea level by more than 200 m plausible, and whe-
ther the equatorial plateau would then still be warm enough to make
the evolution of "reptiles" plausible, but I think my players would ac-
cept that explanation for the history of the planet and the existence of
its "reptiles".

Besides, this could be turned around to become a part of a scientific
puzzle: The existence of the "reptiles" could prove that there must ha-
ve been a period in the planet's history when dry land existed.
I am not yet sure what to make of this, but there could be ways to link
it to something important for the colony, perhaps something like the
existence of fossil fuels ...

 

[alex_greene]

I knew I'd be trumped by a cocky mathematician sooner or later. ;¬)

Scientists THINK

Engineers DO

:twisted:

Poets PO.

 

[alex_greene]

Thank you very much, I have put the idea on my list.

Right now the most nasty animal on Anuira is a cousin of the
Dunkleosteus:
http://en.wikipedia.org/wiki/Dunkleosteus

However, with 571 million square kilometers, the planet is big
enough to provide surprises for the characters for a long time
- even truly big surprises. :twisted:

That is one menacing arthrodire placoderm.

Of course, at some point you're going to have to hand them an injured one with a bite mark taken out of its flank from what looks to be a creature almost three times its size ...

 

[rust]

Of course, at some point you're going to have to hand them an injured one with a bite mark taken out of its flank from what looks to be a creature almost three times its size ...

Yep, but I have to wait until the colony is well established before I can
do this, because otherwise the colonists would probably just pack their
belongings and leave for a less dangerous environment ... :lol:

 

[alex_greene]

There is always room for rumour. It being a marine environment, there ought to be plenty of fishermen to provide a whole library's worth of implausible fish stories to keep the characters amused - slip one little piece of truth in and they'll never notice ...

 

[Anonymous]

http://www.enchantedlearning.com/subjects/dinosaurs/dinos/Ichthyosaur.shtml

 

[rust]

Thank you very much.

 

[Ishmael]

Right now the most nasty animal on Anuira is a cousin of the
Dunkleosteus:
http://en.wikipedia.org/wiki/Dunkleosteus

DOH!
that head reminds me a great deal of an alligator snapper ( snapping turtle )
descriptions of its eating habits too ( fast opening mouth causing suction to push prey into its mouth )

so kind of like an alligator snapping turtle minus its shell.

 

[Madarin Dude]

Well there are always the ten meter long shark eating armored fish. http://en.wikipedia.org/wiki/Dunkleosteus Looking through time there are many odd and dangerous critters. The mind wanders.

 

[rust]

It is from a post in another forum and slightly off topic, but since the
Dunkleosteus has been mentioned, it might perhaps be interesting -
the short tale of the characters' first encounter with such an animal:

With their task explained to them, the characters manned their Mariner
submarine, called for two of the trained dolphins, and went on their first
expedition beyond the shallow Girardin Flat.
The first part of the expedition went very well, almost a kind of sightsee-
ing tour or a BBC documentary about marine life, with lots of unusual
creatures but no real danger.
And then a creature now named Predator A (my version of the Dunkleos-
teus' cousin) began to develop some nutritionary interest in the two dol-
phins.
The next - and almost last - hour of the expedition became a little hectic,
and afterwards the characters had lost an extremely expensive AUV (au-
tonomous underwater vehicle), their Mariner was more than slightly da-
maged (one manipulator arm and all the searchlights gone), and they had
learned that their powerful sonic weapons only make a Predator A really,
really angry.
Only the dolphins had escaped unharmed, because they could swim a
little faster than Predator A and - unlike the characters - were clever
enough to realize that flight was more prudent than fight.
Back at the base, the characters immediately began to design a sonar
buoy system to warn the colony of any big indigenous sea creatures co-
ming close to it, and also to work on ideas for more useful underwater
weapons.
And to care for their dolphins, which are still shocked and refuse to leave
the immediate area of the habitat.

 

[Guardnacho]

I like the "there once was land theory". With that, there could be floating sea weed or Sargasso blooms that reptiles and other former land animals could lay their eggs on as the land disappeared.


If they have issue with the idea there could never be enough ice to melt to flood the planet. It captured 1 or 2 comets. They became temporary moons. As they melt, the comas (water) would fall to the planet making for a century of rain.