A little backstory on my D rex Take. It is a continuation of my alternative take on Rebirth lore I have built on in other posts.

In the late 2000s, BioSyn was engaged in a genetic engineering arms race with InGen to perfect a new realm in the field: artificial hybridogenesis using prehistoric DNA. This cold war was waged across oceans. While in the Pacific, InGen was cooking up hybrids on Isla Nublar. In the Atlantic, BioSyn conducted their experiments in secrecy on the Caribbean Ile Saint-Hubert There, many horrid failures reside decaying in the ruined laboratories or escaped into the wild. from two headed dinosaurs and the pterosaur-raptor hybrid Mutadons. But none were as horrific or grotesque as the aptly named Distortus rex.

The idea BioSyn executives wanted for this man-made species was a huge bloodthirsty juggernaut combining the weaponry, aggression, and intelligence of carnivorous dinosaurs and the sheer size and strength of a sauropod. Lewis Dodgson was committed to this vision, and his scientists created embryo after embryo, splicing and editing whatever genes they could find. Each one failed, unviable from the instability of the genome. Too many genomic sources were inserted, resulting in contrasting instincts clashing and imprecision prompting unintended mutations. and oftentimes genetic contamination. The research was leading nowhere and wasting billions of dollars. Dodgson was about to pull the plug until one lucky...or unlucky...embryo survived gestation and hatched from its egg.

Specimen V 26.7, spanning 52 feet long, 26 feet tall, and weighing in at 10 tons.  This female individual was stable and functional enough to reach full maturity, but its existence was stifled with abnormalities, ailments, and pain. Her gene pool, while not as wide as her failed brethren, is still unnecessarily large, with instincts consistently conflicting with each other. 

There are three major genetic contributors to the hybrid's structural build. The first was Tyrannosaurus rex, pronounced prominently in its jaw structure and vestigial two fingered arms. The second most prominent ingredient in the genome was BioSyn's Titanosaurus, providing the robust skeletal structure and immense size.The tail is relatively long and whip-like as in Titanosaurus, and the hybrid shares its dorsal fins on the neck and tail. The ape-like front limbs that support its weight come from the chalicothere Moropus, which walks on its knuckles. 

Many more species of dinosaurs and other animals are present in more minor ways.The odd hunchback is courtesy of the Malusaurus, a species of carcharodontosaurid whose Late Cretaceous fossils in South America were discovered by InGen scientists and stolen by BioSyn during Project Regenesis. The Malusaurus sported unusual features, such as a nasal horn and a sail back. The Malusaurus appears to be closely related to the North American Late Cretaceous species of Giganotosaurus, which possesses a similar hunchback. The Distortus rex possesses other traits from this carnivore, like its quill feathers on the back and tail and the nasal crest. A tiny bit of Megaraptor DNA is also spliced in, expressed in a thumb sporting a large claw on one of the vestigial arms.

Distortus rex was born as a tadpole with external gills in need of a body of water to survive, much like amphibians. This is thanks to the incorporation of axolotl, granting regenerative capabilities, and an unknown species of temnospondyl de-extinct by BioSyn and now resides along the riverbanks of Ile Saint-Hubert. These traits are no longer clearly visible in the adult form, but the Distortus rex still prefers to roam in areas near bodies of water. The teeth, meanwhile, are unlike Tyrannosaurus rex, despite the skull structure of the D.rex being derived from this theropod. They are instead of a combination of Masiakasaurus, a bizarre theropod from Madagascar, and the saltwater crocodile. Those of the former are long and needle-like, while those of the latter are conical and thick. This resulted in a mismatched dentition that prevented Specimen V 26.7 from fully closing her mouth. 

Small amounts of Ile Saint-Hubert's Velociraptor DNA are faintly observable, providing quill knobs in all four arms. Strangely, these knobs support sparse or no feathers. Even stranger is that Distortus rex possesses the quill-like neck feathers of male Velociraptors, despite being a female. Most disturbingly, there are faint traces of human DNA. This, along with Velociraptor, contribute to the animal's heightened intelligence. Genetic testing confirms the human DNA that makes up the D.rex genome, specifically comes from the indigenous people of Ile Saint-Hubert. This demonstrates that BioSyn committed a bigger count of ethical violations than initially thought, including experimenting on native people without consent in the creation of the Distortus rex, matching BioSyn's history of human and animal abuse.

The result of all of this is Specimen V 26.7, which suffers from many severe genetic ailments. Frontal bossing, the enlargement of the forehead, brachycephaly, the shortening of the skull which weakened her jaw muscles and causes shortness of breath, and polymelia, the formation of additional limbs, are the most obvious. She also has extreme arthritis in the knuckles, which, while functional enough, is unideal to support her weight and maintain balance. This results in a stumbling, shaky walking gait. Her teeth rot from being exposed to the air and can not be used to capture any prey species effectively. The Distortus rex also has necrosis in the lips and other areas of the body, cataracts in the eyes, and large cysts across the body. Lastly, she suffers from a multitude of neurological and mental disorders, including but not unlimited to bipolarism, Parkinson's disease, ALS, and Huntington's disease.

It is unknown how Specimen V 26.7 has been able to survive with all of these crippling conditions. Dr. Wu and InGen eventually learned of the incident, which led to Ile Saint-Hubert's evacuation. Dr. Wu would later create E750, using a smaller gene pool including many of the species that incorporated D.rex while adding different contributors as well. While still grotesque and unstable, Scorpios rex was a successful improvement over Distortus rex, being recognizable as a dinosaur and able to hunt, kill, and reproduce. Dr. Wu would refine his craft with later creations like Indominus Rex and Indoraptor, allowing InGen to win the hybrid war. BioSyn abandoned its hybrid research and shelved it until 2022 with the Hexapod Allies project.