According to a recent update from Colossal Biosciences, the three cute pups that were rescued from extinction last year are doing well and developing.

Before going extinct, animals of this species were known to traverse the Americas around 10,000 years ago. The Dallas-based biotech company Colossal is said to have revived the ancient dire wolves from extinction after they were given a makeover in popular culture by Game of Thrones, which featured a fictionalised version of them.

Colossal revealed earlier last year that they have altered the genetic code of the common grey wolf by using ancient DNA from dire wolves, notably from a 72,000-year-old skull and a 13,000-year-old tooth. ‘Healthy dire wolf babies’ were produced by the experiment, which used domestic canines as surrogate moms.

Experts quickly pointed out that the pictures of snow-white wolves Romulus, Remus, and their younger sister Khaleesi that were posted online were actually “grey wolves that possess 20 edited genes that are meant to give them dire wolf-like features,” not dire wolves.

The three “new” dire wolves had doubled in size in just a few months, growing to be “about 20% larger than a standard grey wolf,” Colossal’s Chief Animal Officer, Matt James, stated in a video.

“Today, Romulus and Remus, at a little over six months old, weigh a little more than 90 pounds, which is about 20% larger than a standard grey wolf,” James stated in the update. “So we can really tell that the dire wolf genes are kicking in and we’re getting these nice large wolves that are much more representative of what we see in the ancient specimens.”

Khaleesi, the youngest of the group, is still smaller than her brothers despite being three months old. She is currently 15%–20% larger than a typical grey wolf at her age, weighing about 35 pounds.

Since the crew is searching for “indicators” that the three would get along, Khaleesi has not yet joined Romulus and Remus.

“Before we make the introduction of bringing Khaleesi into the group with the boys, we’re going to be looking for really strong indicators that they are socially compatible,” explained James. “We’re really excited about that.”

In the meantime, Romulus and Remus have begun to assume distinct responsibilities within their pack-like relationships.

According to Paige McNickle, who oversees the daily care team for the dire wolves, Romulus is becoming more subservient, while Remus has begun to take on an alpha position.

“Remus really likes to watch things, and he figures stuff out,” McNickle said. “He’s also a little bit smaller, so sometimes that’s interesting to think that the smaller of the two would be the more dominant. But he’s crafty and he’s always watching.”

According to McNickle, the pack dynamic may alter after Khaleesi joins her brothers because Romulus is the first to go while the dire wolves feed and play. This is an obvious “beta trait.”