On Dinosaur Reconstruction: An Introduction to Important Topics of Paleontology and Dinosaurs

Many people may be interested in Paleontology since the subject allows for large amounts of imagination and freedom in the creation of scenes. Dinosaurs draw the biggest interest because of their diversity in peculiar forms and often unusually large size of many species. There are people like artists who help the field paleontologists to describe, interpret and reconstruct fossils, and others that create drawings, restorations, sculptures and, most recently, computer animations for science, art and joy. To this end, a successful professional should have specific knowledge that will allow them to produce high-quality work. The current paper aims at: 1) providing knowledge on various topics of Paleontology, in order to understand the time scale of life on earth, its evolution and diversity;2) generating appreciation for the evolution of climatic conditions, continental plates and movement and the Mesozoic environment in which dinosaurs evolved;3) offering an understanding of scientific nomenclature used in Paleontology, and interpretation of drawings and meanings;4) helping one to realize how scientists extract information from bones, tracks, eggs, embryos and other remains;5) examining the physiology of dinosaurs, their metabolism, behaviors, growth rates estimated lifetime and diet;and 6) leading to the understanding of the relations between different dinosaur species and how Paleontologists complete missing parts from uncomplete skeletons. Examining the evolution of life, we observe that life began about 3.8 billion years ago in the deep sea. The first simple animals such as worms and jellyfish appeared in the oceans around 600 mya. The crust of the earth continuously moves to produce changes in the land masses and changes in the climatic conditions that affect the evolution of life. The life of the earth is divided into geological eras. At the end of each geological era, a major event of extinction occurred, which every time obliterated important groups of life. Dinosauria was one of the most successful clades of animals that lived on terrestrial ecosystems for over 160 million years, but was extinct at one of the major extinction events 66 mya. The remains of animals allow scientists and artists to recreate their forms usually in great detail and extract a lot of information about their lives. The paper describes in detail how and where to find information and explains how to interpret them in order to understand the meanings. The paper presents all the above in a simplified way giving the required knowledge without using difficult scientific terms and provides the essential knowledge to the interested person to appreciate the science of Paleontology.

On Dinosaur Reconstruction: Posture of Dinosaurs

Dinosaurs due to their diverse species and peculiar forms have drawn the interest of both artists and scientists. One way to unlock the unknown life of dinosaurs is to reconstruct dinosaurs through drawings, computer animations or sculptures. Following the Introduction on “Dinosaur Reconstruction” by the present authors, where important Paleontological knowledge was presented, the next step is to examine some specific information along with necessary details for dinosaur reconstruction. The first and basic step to be taken for a reconstruction is the posture of the animal;this is the theme of the current paper. Dinosaurs would move either bipedally or quadrupedally depending on their kind and body construction. Based on the available literature, various issues in relation to the posture of an animal at different instances are examined. These are: postures of bipedal dinosaurs during walking, observation of living bipedal animals, postures of quadruped dinosaurs during walking, feeding styles, and dinosaur tails. Theropods had a locomotor behavior like modern birds, with the step width increasing when the animals decreased speed. The general posture and movement of quadrupeds and especially sauropods, remains a subject of great and much controversy. Some scientists believe that sauropod necks were generally held in a neutral or undeflected state during most of the time, while others believe that sauropod necks behaved like all present-day amniote with the mid-cervical region held nearly vertical. Also, there are indications that dinosaurs usually held their tails above ground. For all dinosaurs, the long tail was acting as a counterbalance to the head and body. As a validating example, the case of Amargasaurus is investigated with the help of a model, where the various positions of the animal are examined. A certain posture was chosen for a full-size steel and concrete reconstruction based on the features of the animal.

On Dinosaur Reconstruction: The Head

This paper presents the current knowledge about the reconstruction of dinosaur heads. To reconstruct the dinosaur head, several features and functions of the head must be studied, namely osteology, musculature and soft tissue of the head, cranial kinesis, craniodental biomechanical characteristics, posterior part of the cranium, skin, and others. The main steps and points resulting from the study are the following. Firstly, the osteological remains of the head are studied for reconstruction according to the correct size and form in comparison with known remains belonging to the same family in case the remains were not complete. As the dinosaurs did not have facial muscles, their skin was pressed directly to the skull. The skin covering the large openings in front of the orbits of many dinosaurs probably bulged gently outward, and similarly, the jaw muscles bulged gently from the skull openings. Also, an investigation is performed to decide if sauropods were terrestrial or aquatic animals. Then, the individual characteristics of the head are examined in detail. These concern: 1) endocranial cast and nerves, 2) nostrils position, 3) the existence and kind of cheeks and lips, 4) Teeth types and function, 5) the palate shape and skin covering, 6) hyoid apparatus and tongues, 7) the details of the ear, 8) sclerotic rings and eyes, 9) skin and color. With the knowledge gathered about the various parts of the head in mind, decisions are made about the Amargasaurus (a sauropod) head in order to reconstruct a 3D, actual size head, as a worked example. Finally, the reconstruction procedure is described in detail.