Level 1 — Absolute Beginner

Scientists have found a new kind of dinosaur in Brazil. They named it Dasosaurus tocantinensis. It is a sauropod, which means a big dinosaur with a long neck.

Workers found the first bones in 2021. They were building a new road and rail terminal. The bones were near a town called Davinópolis.

The dinosaur was very big. It was about 20 meters long. That is almost as long as five cars in a row.

Its closest cousin lived in Spain, far away across the sea. This is a surprise. It shows that long-necked dinosaurs could once walk from Europe to South America.

dinosaur

a big animal that lived long, long ago

sauropod

a dinosaur with a long neck, long tail, and small head

fossil

the hard parts of a plant or animal kept in rock for millions of years

Brazil

a large country in South America

Spain

a country in southern Europe

neck

the part of the body between the head and the shoulders

long

of great length

cousin

a close relative

Level 2 — Elementary

On May 15, a team of Brazilian and international scientists published a paper in the Journal of Systematic Palaeontology that names a new dinosaur. They call it Dasosaurus tocantinensis. The name combines the Greek word 'dasos,' meaning forest, and 'saurus,' meaning lizard, with a reference to the nearby Tocantins River.

The first bones of Dasosaurus were found in 2021 by an archaeologist named Daniel Ribeiro da Silva. He noticed them during the construction of a road and rail terminal in Davinópolis, in the northeastern state of Maranhão. The rocks that held the fossils belong to a unit called the Itapecuru Formation, which dates to the Early Cretaceous, about 115 to 120 million years ago.

The dinosaur was a sauropod — one of the long-necked, plant-eating giants. Scientists estimate that Dasosaurus stretched about 20 meters from nose to tail. They found tail bones, a 1.5-meter thigh bone, ribs, foot bones, and parts of the arms and legs.

Most surprisingly, when researchers compared Dasosaurus to other sauropods around the world, its closest match was Garumbatitan, a dinosaur known from Spain. At the time, the Atlantic Ocean was already starting to open, but the two animals still shared a recent ancestor. The discovery is fresh evidence that some land bridge or short crossing must have linked Europe, Africa and South America for millions of years longer than scientists once thought.

paper

a written scientific report

archaeologist

a person who studies the human past from objects in the ground

construction

the work of building something

formation

a layer of rock with a single name

Cretaceous

a long period of Earth history when dinosaurs lived, ending 66 million years ago

thigh bone

the large bone in the upper leg

ancestor

a relative from many generations earlier

land bridge

a strip of land that once joined two areas that are now separated by water

Level 3 — Intermediate

A team led by Brazilian paleontologist Elver L. Mayer announced on May 15 the formal description of a new genus and species of long-necked dinosaur from northeastern Brazil, published in the Journal of Systematic Palaeontology. The animal has been named Dasosaurus tocantinensis — combining the Greek 'dasos' (forest) with 'saurus' (lizard) and a reference to the Tocantins River, which flows near the type locality.

The holotype, catalogued as CPHNAM VT 1600 in the collections of the Federal University of Maranhão, was uncovered in 2021 by archaeologist Daniel Ribeiro da Silva during environmental monitoring of a road-rail terminal construction site at Davinópolis, in northeastern Maranhão. The fossils were exposed at the base of an eight-meter slope of Itapecuru Formation sandstones and mudstones laid down during the Aptian stage of the Early Cretaceous, roughly 115–120 million years ago.

Recovered material includes a partial caudal series of at least ten disarticulated tail vertebrae, ribs, a 1.5-meter femur, a tibia and fibula, a partial ulna and radius, and the pubis and ischium of the pelvis. Body-length estimates place Dasosaurus at around 20 meters from snout to tail, with a body mass approaching that of a small modern blue whale. The animal is classified within the Somphospondyli, a major clade of titanosauriform sauropods.

The phylogenetic surprise lies in its closest relative. When the team scored Dasosaurus against a broad sample of Early Cretaceous sauropods, the analysis placed it as a sister to Garumbatitan morellensis, known from late Barremian rocks in Spain. The implication is that even after Gondwana and Laurasia had started to fragment and the Atlantic was widening, somphospondylan sauropods retained enough biogeographic connectivity to share ancestry between Iberia and northern South America.

paleontologist

a scientist who studies fossils

holotype

the single specimen used to define a new species

environmental monitoring

checking a site for natural or cultural impact, often before construction

Aptian

a stage of the Early Cretaceous between about 125 and 113 million years ago

caudal

relating to the tail

pelvis

the lower part of the body that holds the hips

clade

a group of organisms that includes an ancestor and all its descendants

biogeographic connectivity

the ability of species to move between regions

Level 4 — Advanced

An international team led by Brazilian paleontologist Elver L. Mayer formally erected a new genus and species of long-necked dinosaur, Dasosaurus tocantinensis, in the Journal of Systematic Palaeontology on May 15. The generic name conjoins the Greek 'dasos' (forest) — a nod to the Amazônia Legal region surrounding the type locality — with 'saurus' (lizard); the specific epithet honours the nearby Tocantins River. The paper, co-authored by sixteen specialists from Brazilian, European and U.S. institutions, frames the new taxon as a meaningful addition to the patchily sampled Aptian sauropod record of northern South America.

The holotype (CPHNAM VT 1600), curated at the Federal University of Maranhão, was recovered in 2021 by archaeologist Daniel Ribeiro da Silva during legally mandated environmental monitoring of a road-rail terminal construction site at Davinópolis, Maranhão. The fossils were exposed at the base of an approximately eight-meter slope cut through fluvial sandstones and overbank mudstones of the Itapecuru Formation, deposited during the Aptian stage of the Early Cretaceous, approximately 115–120 million years ago.

Recovered skeletal elements include at least ten disarticulated caudal vertebrae, ribs, a 1.5-meter femur, tibia and fibula, partial radius and ulna, several phalanges, and the pubis and ischium. Quantitative size estimates place Dasosaurus at approximately 20 meters total length and tens of tonnes in mass, placing it among the larger sauropods so far described from the formation. Histological sectioning of long-bone shafts indicates rapid sustained growth typical of titanosauriform giants, with limited remodeling of the cortical tissue.

The phylogenetic upshot is biogeographically significant. Across multiple parsimony and Bayesian iterations of a broadly sampled Sauropoda matrix, Dasosaurus recovers as the sister taxon to Garumbatitan morellensis from the late Barremian Arcillas de Morella Formation of eastern Spain. Given the Aptian palaeogeography of the proto-Atlantic, the relationship requires either a still-passable Atlantic narrow or — more plausibly — a longer-than-supposed window of sporadic dispersal between Iberia, North Africa and northern Gondwana. The finding bolsters a growing case that Early Cretaceous somphospondylan sauropods maintained transcontinental phylogenetic ties well after the canonical models had them isolated.

erect

to formally establish a new scientific name

epithet

the second part of a scientific name, specifying the species

type locality

the place where a species's holotype was collected

fluvial

made by rivers

overbank

deposits left by floodwaters spilling over a riverbank

histological sectioning

cutting and examining thin slices of bone tissue under a microscope

parsimony