The Sea Dragons – Evolutionary Lineup
Each species shown is a snapshot along the evolutionary journey from land-dwelling lizards to fully aquatic marine predators:
1. Aigialosaurus dalmaticus
-
Time: ~100–93 million years ago (mya)
-
Location: Croatia
-
Traits: Early semi-aquatic form, retains more lizard-like limbs
2. Dallasaurus turneri
-
Time: ~92 mya
-
Location: USA
-
Traits: Transitional form with more elongated body and webbed limbs for swimming
3. Yaguarasaurus columbianus
-
Time: ~90 mya
-
Location: Colombia
-
Traits: Larger, more streamlined for aquatic life; reduced limb function, more developed flippers
4. Halisaurus platypterygius
-
Time: 70–66 mya
-
Location: USA
-
Traits: Fully aquatic; tail adapted for propulsion, more fish-like appearance
5. Platecarpus tympanicus
-
Time: 84–81 mya
-
Location: USA / Canada
-
Traits: Advanced mosasaur; powerful tail, streamlined body, large paddle-like limbs
6. Plotosaurus bennisoni
-
Time: 70–66 mya
-
Location: USA
-
Traits: One of the most advanced and fastest mosasaurs; fluke-shaped tail like modern whales and dolphins
🧬 Evolutionary Insight:
-
This series doesn’t imply direct ancestry but rather shows evolutionary trends within the mosasaur group.
-
Transitioned from land-walking lizards to hydrodynamic marine predators.
-
Each form reflects greater aquatic specialization: limb reduction, tail fin development, and body streamlining.