Near the village Abella de la Conca, in the 1990s, palaeontologist Marc Boada discovered a new site in the Talarn Formation, bearing dinosaur fossils.
From this site, later named Les Llaus (LL), a right dentary, specimen designation IPS SRA 27, was excavated.
In 1997, Casanovas-Cladellas and colleagues stated this dentary was discovered from SRA, the site where the original Pararhabdodon remains were found.
The following year, they described the specimen and referred it to P. isonensis, and again stated it was from the same stratigraphic level.
In 2006, the stratigraphy of the region was re-evaluated, and the dentary's location was corrected to the LL locality, 750 metres (2,460 ft) away from and 9 metres (30 ft) below the SRA locality.

The same 2006 study, by Albert Prieto-Márquez and colleagues, noted that no dentary had been found at the SRA locality to compare to the LL specimen, and so they restricted P. isonensis to material known from its original locality.
Additionally, they named a genus and species for IPS SRA 27, Koutalisaurus kohlerorum.
The generic name is derived from the Greek word koutali, meaning spoon, in reference to the shape the jaw of the animal would've had, and the specific name honours Terry and Mary Kohler, for their support of vertebrate paleontology.
One autapomorphy (unique trait) was used to diagnose the taxon as a new species: a very elongated edentulous section on the dentary, which was medially (inwardly) extended.
No teeth were preserved, but there are 35 tooth positions.
Several other European hadrosaur dentaries were compared based on published data, and the specimen was found to be unique compared to all of them.
Though the specimen proved too fragmentary to be used for phylogenetic analysis, it was determined to be a hadrosaurid of some kind, more derived than Pararhabdodon, considered the sister taxon to Hadrosauridae.
The authors noted the possibility future discoveries could lead to synonymization of their taxon with P. isonensis
Evidence for this synonymy would later come in a 2009 study, from Prieto-Márquez alongside Jonathan R. Wagner.
Material from Pararhabdodon, the holotype of Koutalisaurus, and material of the Chinese species Tsintaosaurus spinorhinus were examined and compared, and the edentulous slope previously thought unique to Koutalisaurus was found to be nearly identical in T. spinorhinus.
It was noted various approaches could be taken to this matter.
As the species K. koelerororum shared a unique trait with Tsintaosaurus and could not be distinguished from it, the former could be considered a junior synonym of the latter.
However, it was noted that the likelihood of a large archosaur species with a large enough range to include both specimens is completely unprecedented, so they refrained from this referral.
K. kohlerorum could instead be considered a nomen dubium, a taxon of uncertain distinctiveness due to lacking any autapomorphies.
But they disliked this course of action too, as unless a second taxon with the same morphology was found in the area, they posited the specimen likely did represent a unique component of the local fauna.
Thus, they decided to keep it distinct, relative to Tsintaosaurus.
No material had, as yet, been discovered from the SRA locality permitting comparison with Pararhabdodon.
However, traits uniting P. isonensis with T. spinorhinus were found.
As both taxa from the Talarn Formation uniquely shared traits with the Asian genus, the authors decided to treat the two as one species, as maintaining them as provisionally separate would in their eyes be misleading to non-specialists, who would likely not distinguish the two taxa were kept separate to be conservative and not due to strong evidence for two hadrosaurs in the area.

Prieto-Márquez returned again to the dentary in 2013, in a study alongside colleagues providing a review and investigation of hadrosaurs from all over Europe.
Further preparation of the specimen in the time since his last study regarding it revealed the uniqueness of the dentary had been exaggerated significantly by recon
Near the village Abella de la Conca, in the 1990s, palaeontologist Marc Boada discovered a new site in the Talarn Formation, bearing dinosaur fossils. From this site, later named Les Llaus (LL), a right dentary, specimen designation IPS SRA 27, was excavated. In 1997, Casanovas-Cladellas and colleagues stated this dentary was discovered from SRA, the site where the original Pararhabdodon remains were found. The following year, they described the specimen and referred it to P. isonensis, and again stated it was from the same stratigraphic level. In 2006, the stratigraphy of the region was re-evaluated, and the dentary's location was corrected to the LL locality, 750 metres (2,460 ft) away from and 9 metres (30 ft) below the SRA locality.
The same 2006 study, by Albert Prieto-Márquez and colleagues, noted that no dentary had been found at the SRA locality to compare to the LL specimen, and so they restricted P. isonensis to material known from its original locality. Additionally, they named a genus and species for IPS SRA 27, Koutalisaurus kohlerorum. The generic name is derived from the Greek word koutali, meaning spoon, in reference to the shape the jaw of the animal would've had, and the specific name honours Terry and Mary Kohler, for their support of vertebrate paleontology. One autapomorphy (unique trait) was used to diagnose the taxon as a new species: a very elongated edentulous section on the dentary, which was medially (inwardly) extended. No teeth were preserved, but there are 35 tooth positions. Several other European hadrosaur dentaries were compared based on published data, and the specimen was found to be unique compared to all of them. Though the specimen proved too fragmentary to be used for phylogenetic analysis, it was determined to be a hadrosaurid of some kind, more derived than Pararhabdodon, considered the sister taxon to Hadrosauridae. The authors noted the possibility future discoveries could lead to synonymization of their taxon with P. isonensis
Evidence for this synonymy would later come in a 2009 study, from Prieto-Márquez alongside Jonathan R. Wagner. Material from Pararhabdodon, the holotype of Koutalisaurus, and material of the Chinese species Tsintaosaurus spinorhinus were examined and compared, and the edentulous slope previously thought unique to Koutalisaurus was found to be nearly identical in T. spinorhinus. It was noted various approaches could be taken to this matter. As the species K. koelerororum shared a unique trait with Tsintaosaurus and could not be distinguished from it, the former could be considered a junior synonym of the latter. However, it was noted that the likelihood of a large archosaur species with a large enough range to include both specimens is completely unprecedented, so they refrained from this referral. K. kohlerorum could instead be considered a nomen dubium, a taxon of uncertain distinctiveness due to lacking any autapomorphies. But they disliked this course of action too, as unless a second taxon with the same morphology was found in the area, they posited the specimen likely did represent a unique component of the local fauna. Thus, they decided to keep it distinct, relative to Tsintaosaurus. No material had, as yet, been discovered from the SRA locality permitting comparison with Pararhabdodon. However, traits uniting P. isonensis with T. spinorhinus were found. As both taxa from the Talarn Formation uniquely shared traits with the Asian genus, the authors decided to treat the two as one species, as maintaining them as provisionally separate would in their eyes be misleading to non-specialists, who would likely not distinguish the two taxa were kept separate to be conservative and not due to strong evidence for two hadrosaurs in the area.
Prieto-Márquez returned again to the dentary in 2013, in a study alongside colleagues providing a review and investigation of hadrosaurs from all over Europe. Further preparation of the specimen in the time since his last study regarding it revealed the uniqueness of the dentary had been exaggerated significantly by recon
Pararhabdodon