| Lophorhothon | |
|---|---|
 | |
| Skeletal elements | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Clade: | Dinosauria |
| Clade: | †Ornithischia |
| Clade: | †Ornithopoda |
| Clade: | †Hadrosauromorpha |
| Genus: | †Lophorhothon Langston, 1960 |
| Type species | |
| †Lophorhothon atopus Langston, 1960 | |
Lophorhothon is agenus ofhadrosauroiddinosaur from theLate Cretaceous ofAlabama, and possiblyGeorgia andNorth Carolina. It was the first dinosaur genus discovered in Alabama, in theUnited States.
Remains of a small, poorly known perhapssaurolophine dinosaur were first discovered during the 1940s, from extensive erosional outcrops of the lower unnamed member of theMooreville Chalk Formation (Selma Group; lower and middleCampanian) inDallas County, west of the town ofSelma, Alabama. The taxon has since also been reported fromBlack Creek Formation (Campanian) ofNorth Carolina.[1] Theholotype, which is housed in the collections of theField Museum in Chicago, consists of a fragmentary and disarticulated skull and incomplete postcranial skeleton. The length on the holotype specimen has been estimated as 4.5 metres (14 ft 9 in). Which is small for a hadrosaur, but the original specimen is of a juvenile. The adults may have been larger, probably as large asHadrosaurus,Hypsibema,Kritosaurus, andGryposaurus. The genus was named byWann Langston in 1960. It was thought to be the only species of hadrosaur from thatfossil formation, until 2016 with the discovery of the primitive hadrosaur,Eotrachodon orientalis. The nameLophorhothon means "crested nose" (Greeklophos meaning 'crested' andrhothon meaning 'nose'). Thetype species isLophorhothon atopus. Thespecific name is derived from Greekatopos, "uncommon" or "strange".
The specimen which Langston designated as the holotype was discovered by Rainier Zangerl, Bill Turnbull and Charles Barber on a Field Museum expedition in 1946 and was given catalogue number FMNH P 27383. It consists of less than one half of the skull, a number ofvertebrae, and significant portions of the fore- and hindlimbs. Preserved cranial material includes a partial quadrate, left maxilla, teeth, jugal, lacrimal, nasal (with the namesake crest), postorbital, frontal, prefrontal, parietal, squamosal, and paroccipital process and a portion of the predentary bone. The specimen was likely washed out to sea by a river, where it eventually sank and was buried in the siltycarbonate sediments of theMississippi embayment.
In 2021, a more complete specimen was unearthed in Alabama.[2]
Since the publication of Langston's description ofLophorhothon a number of workers have questioned the validity of thisgenus. It has been suggested, for example, that the material may actually represent a juvenileProsaurolophus. James Lamb in 1998 has suggested the genus may actually represent a basaliguanodont, an idea that has failed to find widespread acceptance. More recent workers (Horner, Weishampel, and Forster, 2004) have classifiedLophorhothon as a basal hadrosaurine and a sister taxon to all other hadrosaurines. An analysis published in 2010 indicated it was a basal member of theHadrosauroidea.[3]
In 2021, new material from Alabama was unearthed not too far from where the original holotype was unearthed. This find cemented its status as a valid genus ofhadrosauromorph.[4]
