#bisticeratops

Changmiania liaoningensis

Artwork by @i-draws-dinosaurs, written by @zygodactylus

Name Meaning: Eternal Sleeper from Liaoning

Time: 125.755 million years ago (Barremian stage of the Early Cretaceous) 

Location: Lujiatun Beds, Yixian Formation, Liaoning, China 

Changmiania is a gorgeously preserved ornithopod known from the earliest time of the famed Yixian Formation, adding it to the ranks of amazing fossils known from this unique preservational environment. The multiple specimens of this species are found in sleeping poses, curled up on the ground with their legs and arms tucked up against them. This indicates they had been buried alive, possibly inside their own burrows. Given the depositional environment of Yixian is a sort of prehistoric Pompeii, with many dinosaurs covered very quickly in ash and dust from an exploding volcano, this makes a certain degree of sense - perhaps the two little dinosaurs had scurried into their burrow to escape the oncoming tragedy (sorry if I just made you sad), or had been asleep and unaware of the oncoming danger. At only one meter long and less than half a meter tall, Changmiania would have been easily missed in its environment, hiding among the dense vegetation from potential predators. With robust leg bones, it would have been a fast runner, able to move efficiently through the crowded undergrowth. It had a weirdly short neck for ornithischians, and that combined with its short forearms and hands indicates it was fossorial - ie, a digging animal, hence its burrow home and final resting place. Given they were found together, they were probably social creatures as well, living in small family groups. The Yixian was a dense temperate forest, filled with freshwater lakes and a great diversity of plantlife. Conifers, ferns, cycads, horsetails, and early flowering plants filled the environment and indicated a humid, possibly rainforest environment. Periodic wildfires, noxious lake gasses, and volcanic eruptions all lead to regular moments of rapid burial and amazing preservation in this environment - essentially giving us snapshots of how it changed over the course of many millions of years. In the Lujiatun bed specifically, Changmiania was neighbors with Euhelopus, Jeholosaurus, Liaoceratops, Psittacosaurus, Liaoningornis, Daliansaurus, Graciliraptor, Mei, Sinovenator, Sinusonasus, Dilong, Hexing, Incisivosaurus, Shenzhousaurus, and outside of dinosaurs mammals such as Acristatherium, Gobiconodon, Juchilestes, Maotherium, Meemannodon, and Repenomamus (yes, THAT Repenomamus), and the toad Liaobatrachus. 

Bisticeratops froeseorum

Artwork by sauriazoicillus, written by @zygodactylus

Name Meaning: Froese’s Dééł Náázíní Horned Face 

Time: 74 million years ago (Campanian stage of the Late Cretaceous) 

Location: Farmington Member, Kirtland Formation, New Mexico, United States 

Bisticeratops is an early Chasmosaurine, known from a partial skull found in the Kirtland Formation. Yet another of a largely growing number of Chasmosaurine taxa from the Campanian of North America, it appeared to resemble Pentaceratops, but was more closely related to later ceratopsians known from the Kirtland formation, as well as one unnamed taxon from the Almond Formation in Wyoming. Interestingly, Bisticeratops shows signs of bite marks from tyrannosaurids, which apparently had begun to heal prior to death. However, we do not know which tyrannosaurid may have left these marks - while the Kirtland Formation is a well studied environment, the Farmington Member has never yielded dinosaurian fossils before now, taking place earlier than the more famous De-Na-Zin of the formation. Like other iterations, the Kirtland was a coastal plain along the western interior seaway, preserving a muddy and sandy environment that would have been filled with a variety of subtropical plants. It is presumable that other dinosaurs lived here besides Bisticeratops and a tyrannosaurid - hadrosaurs, ankylosaurs, pachycephalosaurs, ornithomimosaurs, and dromaeosaurs would all have been possible members of this ecosystem based on the following and preceding ones from this formation.

(Type skull of Bisticeratops froeseorum, from Dalman et al., 2022)

Meaning of name: Bisticeratops = Bisti/De-na-zin Wilderness Area horned face [in Greek]; froeseorum = for Edgar Froese [the late founder of the band Tangerine Dream] and Jerome Froese [former member of Tangerine Dream and founder of the band Loom]

Age: Late Cretaceous (Campanian), about 74 million years ago

Where found: Kirtland Formation, New Mexico, U.S.A.

How much is known: Nearly complete skull of one individual.

Notes: Bisticeratops was a chasmosaurine ceratopsian, making it a fairly close relative of Triceratops. The holotype skull of Bisticeratops was originally considered a specimen of Pentaceratops, another chasmosaurine from the Campanian of New Mexico. However, a new study identifies several distinguishing features that suggest it is a separate species. In addition, Bisticeratops is approximately 2 million years younger than Pentaceratops proper. Along with several other recently named ceratopsians, such as Sierraceratops, Navajoceratops, and Terminocavus, Bisticeratops shows that chasmosaurine diversity was very high in the Campanian of southwestern North America.

The Bisticeratops type specimen is also noteworthy in that it preserves multiple bite marks that were likely made by tyrannosaurids. One of these bite marks shows signs of healing, indicating that this individual had survived at least one attack from a predator.

Bisticeratops

Bisticeratops — рід хазмозавринових цератопсів із відслонень Киртландської формації кампанського періоду, знайдений в пустелі Бісті/Де-На-Зін на північному заході Нью-Мексико, США. Типовий і єдиний вид — B. froeseorum, відомий за майже повним черепом.

Повний текст на сайті "Вимерлий світ":

Bisticeratops froeseorum

Artwork by sauriazoicillus, written by @zygodactylus

Name Meaning: Froese’s Dééł Náázíní Horned Face 

Time: 74 million years ago (Campanian stage of the Late Cretaceous) 

Location: Farmington Member, Kirtland Formation, New Mexico, United States 

Bisticeratops is an early Chasmosaurine, known from a partial skull found in the Kirtland Formation. Yet another of a largely growing number of Chasmosaurine taxa from the Campanian of North America, it appeared to resemble Pentaceratops, but was more closely related to later ceratopsians known from the Kirtland formation, as well as one unnamed taxon from the Almond Formation in Wyoming. Interestingly, Bisticeratops shows signs of bite marks from tyrannosaurids, which apparently had begun to heal prior to death. However, we do not know which tyrannosaurid may have left these marks - while the Kirtland Formation is a well studied environment, the Farmington Member has never yielded dinosaurian fossils before now, taking place earlier than the more famous De-Na-Zin of the formation. Like other iterations, the Kirtland was a coastal plain along the western interior seaway, preserving a muddy and sandy environment that would have been filled with a variety of subtropical plants. It is presumable that other dinosaurs lived here besides Bisticeratops and a tyrannosaurid - hadrosaurs, ankylosaurs, pachycephalosaurs, ornithomimosaurs, and dromaeosaurs would all have been possible members of this ecosystem based on the following and preceding ones from this formation.

Gobihadros mongoliensis

Artwork by KookaburraSurvivor, written by @zygodactylus

Name Meaning: Hadrosaur from the Gobi of Mongolia 

Time: 90 to 86 million years ago (Turonian to Coniacian stages of the Late Cretaceous)

Location: Upper Beds, Bayan Shireh Formation, Bayshin Tsav, Baynshire, Char Teeg, Khongil Tsav, Khoorai Tsav, Mongolia 

Gobihadros is an early almost-hadrosaur from the Bayan Shireh Formation, one of the rare environments preserving the evolution of dinosaurs during the start of the Late Cretaceous epoch - essentially, when the charismatic dinosaurs of the Latest Cretaceous, such as hadrosaurs, first evolved. Multiple specimens are known from throughout the formation, making Gobihadros the best known early hadrosauroid from Asia. Adults reached sizes of about 7.5 meters long, and it had as many as three teeth per position within the lower jaw (this is high even for early hadrosaurs, more similar to those of later taxa, indicating convergent/parallel evolution). It also still retained the conical thumb claw of earlier ornithopods like Iguanodon. An older individual of the species showed signs of calcium pyrophosphate deposition disease, a condition of age causing restriction in the joints and pain during movement. Gobihadros lived in a semi-arid plain environment littered with lakes and rivers, with meandering bodies of water draining into the sea on the coast of China. Flowering plants were present in this environment, as well as a wide variety of animal life - sharks, Azhdarchids, turtles, and other dinosaurs like Alectrosaurus (probably), a troodontid, Erlikosaurus, Caenagnathoids, Garudimimus, Graciliceratops, a possible Carcharodontosaur (which would be a late surviving species), Talarurus, and potentially many more species waiting to be formally named.

Factfiles:

Bisticeratops froeseorum

Artwork by sauriazoicillus, written by @zygodactylus

Name Meaning: Froese’s Dééł Náázíní Horned Face 

Time: 74 million years ago (Campanian stage of the Late Cretaceous) 

Location: Farmington Member, Kirtland Formation, New Mexico  Bisticeratops is an early Chasmosaurine, known from a partial skull found in the Kirtland Formation. Yet another of a largely growing number of Chasmosaurine taxa from the Campanian of North America, it appeared to resemble Pentaceratops, but was more closely related to later ceratopsians known from the Kirtland formation, as well as one unnamed taxon from the Almond Formation in Wyoming. Interestingly, Bisticeratops shows signs of bite marks from tyrannosaurids, which apparently had begun to heal prior to death. However, we do not know which tyrannosaurid may have left these marks - while the Kirtland Formation is a well studied environment, the Farmington Member has never yielded dinosaurian fossils before now, taking place earlier than the more famous De-Na-Zin of the formation. Like other iterations, the Kirtland was a coastal plain along the western interior seaway, preserving a muddy and sandy environment that would have been filled with a variety of subtropical plants. It is presumable that other dinosaurs lived here besides Bisticeratops and a tyrannosaurid - hadrosaurs, ankylosaurs, pachycephalosaurs, ornithomimosaurs, and dromaeosaurs would all have been possible members of this ecosystem based on the following and preceding ones from this formation.

Crittendenceratops krzyzanowskii

Artwork by PaleoEquii, written by @zygodactylus

Name Meaning: Krzyzanowski’s Horned Face from Crittenden

Time: 73 million years ago (Campanian stage of the Late Cretaceous) 

Location: Fort Crittenden Formation, Arizona Crittendenceratops is the first ever dinosaur named formally from the Fort Crittenden Formation, an alluvial plain filled with lakes and rivers and frequently shifting environments. This environment was very associated with water, with many types of gastropods and bivalves found in the ecosystem. Other dinosaurs have also been found here, but none have been named - including dromaeosaurids and a hadrosaurid. Amphibians, alligators, fish, and turtles also lived in this ecosystem. Crittendenceratops itself was a small Centrosaurine, only about 3.4 meters long, and it had small forward-curving hooks flanging off of the top of the frill, a thick nasal bone, and ridges on the back of the frill. It also had small curved horns above its eyes. It seemed to resemble Nasutaceratops, and appears to have been in a group with that and other similar Centrosaurines.