Saurolophinae Temporal range:Late Cretaceous,83–66 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Fossil mount ofEdmontosaurus
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Dinosauria
Clade:	†Ornithischia
Clade:	†Ornithopoda
Family:	†Hadrosauridae
Clade:	†Euhadrosauria
Subfamily:	†Saurolophinae Lambe, 1918
Type species
†Saurolophus osborni Brown, 1912
Tribes and genera[1]
†Barsboldia †AustrokritosauriaAlarcón-Muñozet al., 2023 †Bonapartesaurus †Huallasaurus †Kelumapusaura †Secernosaurus †BrachylophosauriniGateset al., 2011 †Acristavus †Brachylophosaurus †Maiasaura †Ornatops †Probrachylophosaurus †Wulagasaurus? †EdmontosauriniLambe, 1917 †Edmontosaurus †Kamuysaurus †Kerberosaurus †Kundurosaurus †Laiyangosaurus †Shantungosaurus †KritosauriniBrown, 1910 †Ahshislesaurus †Anasazisaurus †Coahuilasaurus †Gryposaurus †Kritosaurus †Naashoibitosaurus †Rhinorex †SaurolophiniGodefroitet al., 2012 †Augustynolophus †Prosaurolophus †Saurolophus

Saurolophinae is asubfamily ofhadrosauriddinosaurs. It has since the mid-20th century generally been called theHadrosaurinae, a group of largely non-crested hadrosaurs related to the crested sub-familyLambeosaurinae. However, the name Hadrosaurinae is based on the genusHadrosaurus which was found in more recent studies to be more primitive than either lambeosaurines or other traditional "hadrosaurines", likeEdmontosaurus andSaurolophus. As a result of this, the name Hadrosaurinae was dropped or restricted toHadrosaurus alone, and the subfamily comprising the traditional "hadrosaurines" was renamed the Saurolophinae.^[1] Recent phylogenetic work by Hai Xing indicates thatHadrosaurus is placed within the monophyletic group containing all non-lambeosaurine hadrosaurids.^[2] Under this view, the traditionalHadrosaurinae is resurrected, with theHadrosauridae being divided into two clades:Hadrosaurinae andLambeosaurinae.

Saurolophinae was first defined as aclade in a 2010 phylogenetic analysis by Prieto-Márquez.^[3] Traditionally, the "crestless" branch of the familyHadrosauridae had been namedHadrosaurinae. However, the use of the term Hadrosaurinae was questioned in a comprehensive study of hadrosaurid relationships by Albert Prieto-Márquez in 2010. Prieto-Márquez noted that, though the name Hadrosaurinae had been used for the clade of mostly crestless hadrosaurids by nearly all previous studies, its type species,Hadrosaurus foulkii, has almost always been excluded from the clade that bears its name, in violation of the rules for naming animals set out by theICZN. Prieto-Márquez (2010) defined Hadrosaurinae as only the lineage containingH. foulkii, and used the name Saurolophinae instead for the traditional grouping.^[3]

In a 2023 study, Alarcón-Muñozet al. implemented an updated version of the phylogenetic matrix of Rozadillaet al. (2022) to analyze the relationships of saurolophines and hadrosaurids. The results of theirphylogenetic analyses of Saurolophinae are displayed in thecladogram below.^[4]

Theclade Brachylophosaurini was defined by Terry Gates and colleagues in 2011 as "Hadrosaurine ornithopods more closely related toBrachylophosaurus,Maiasaura, orAcristavus than toGryposaurus orSaurolophus".^[5] In 2021, Madzia et al. registered Brachylophosaurini in the PhyloCode and formally defined it as "The largest clade containingBrachylophosaurus canadensis but notEdmontosaurus regalis,Hadrosaurus foulkii,Kritosaurus navajovius andSaurolophus osborni".^[6]

The name "Kritosaurini" was first mentioned in 1955 byLapparent &Lavocat, where they mentioned "'Kritosaurinés" as a group of hadrosaurids containing onlyKritosaurus, which was thought of as asenior synonym ofGryposaurus at the time.^{[citation needed]} In 1989,Michael Brett-Surman proposed the name Kritosaurini as atribe ofhadrosaurines that containedAralosaurus,Brachylophosaurus,Hadrosaurus, andKritosaurus (includingGryposaurus).^[7] It was not until 2014 that Albert Prieto-Márquez officially defined and diagnosed Kritosaurini as the most exclusive clade of hadrosaurids containingKritosaurus navajovius,Gryposaurus notabilis, andNaashoibitosaurus ostromi.^[8] Madiaet al. (2021) defined the term under PhyloCode as "the largest clade containingKritosaurus navajovius but notBrachylophosaurus canadensis,Edmontosaurus regalis,Hadrosaurus foulkii,Saurolophus osborni.^[6] In 2022, Rozadillaet al. describedHuallasaurus andKelumapusaura, two new genera similar to kritosaurins. In their study, they analyzed the relationships of the Kritosaurini and Hadrosauridae as a whole.^[9] In a study the following year, Alarcón-Muñozet al. implemented an updated version of the phylogenetic matrix of Rozadillaet al, proposing the nameAustrokritosauria for the clade of entirely South American saurolophines closely related to kritosaurins. This clade was defined as "the most inclusive clade containingHuallasaurus but notGryposaurus".^[4]

Alarcón-Muñozet al. (2023) suggested that austrokritosaurs shared an ancestor with the North Americankritosaurins in theSantonian, about 85 million years ago, beforedispersing into South America. This likely occurred via island chains andrafting. The South AmericanhadrosauroidGonkoken appears to have diverged from North American hadrosauroids at an even earlier time, about 91 million years ago in theTuronian.^[4] The North AmericantitanosaurAlamosaurus may have experienced a similar dispersal events from relatives in South America in the lateCampanian–earlyMaastrichtian.^[10]

• Timeline of hadrosaur research

• Saurolophinae
• Dinosaur subfamilies
• Late Cretaceous dinosaurs

• Articles with short description
• Short description is different from Wikidata
• Articles with 'species' microformats
• All articles with unsourced statements
• Articles with unsourced statements from June 2024