A week after the tiktaalik mission, the park is tasked with traveling to the Silurian period for the very first time for the sake of rescuing the unique species of fish and sea scorpion that were alive in the world at that time. Unfortunately, this time Drew has no other choice but to allow his ex Cynthia to finally directly accompany him on the mission, a prospect that neither of them are entirely looking forward to doing...
- Adaptational Late Appearance: In Prehistoric Earth, Hedetet the pterygotus was rescued in the third episode of 'Phase 1' (and of the entire story as a whole). In this continuity, she finally makes her debut in the third episode of 'Phase 2'.
- Always a Bigger Fish: A megamastax, previously established in the episode as one of the apex predators of the Silurian period China region that the rescue team is exploring for this episode's rescue mission, is easily taken down and torn apart by one of the pterygotus.
- Babies Ever After: It is properly revealed in this episode that the dimetrodon have successfully hatched eggs and obtained offspring.
- Big Creepy-Crawlies: Compared to modern day true scorpions, the brontoscorpio are about the same size as Spiny the juvenile dimetrodon, the terropterus are similarly sized, and the adult pterygotus are at least the size of modern day alligators.
- Gentle Giant: While fairly startling over the course of their introduction, the pterygotus ultimately prove to be surprisingly docile and easy to work with once they've been brought to the park.
- Interspecies Friendship: It is properly revealed in this episode that the harpactognathus egg John Willowby was attending to back in Phase 1 has successfully hatched into a young harpactognathus named Forestock, whom he is currently training to work with him in the security division.
- Mama Bear: Hedetet the pterygotus is very quick to grab and tear apart a megamastax during her time in the Silurian period when she catches it sniffing around the area where her young are hiding. And she also very swiftly snaps her claws in Jack's direction when she catches him swimming towards her and her feeding offspring not too long after she's killed and fed the luckless megamastax to said offspring.
- Mythology Gag:
- Shares a title and several narrative/plot events with an early 'phase 1' chapter of Prehistoric Earth.
- Much like in the aforementioned fic, Cynthia proves to be fairly antagonistic towards Jack over the course of their time together with Drew on this mission.
- Scary Scorpions: Played with in regards the three species of sea scorpion present in the episode. For starters, none of them are truly scorpions. Secondly, the terropterus are successfully sent through the portal and rescued without causing any trouble for the team. And thirdly, while the brontoscorpio and pterygotus both prove fairly startling in their introductory scenes, neither of them prove any more dangerous and aggressively violent than any other animal (with the latter, in particular, turning out to be gentle giants).
