All about dinosaurs, fossils and prehistoric animals by Everything Dinosaur team members.
19 10, 2014

Nosing Around Dinosaurs

By | October 19th, 2014|Dinosaur and Prehistoric Animal News Stories, Main Page|0 Comments

New Study Sniffs Out Details of the Pachycephalosaur Nose

A study into the nasal passages conducted by a team of scientists from Ohio University suggests that certain types of dinosaur used their complicated noses to help cool their brains as well as to enhance their ability to smell.  The study, which focused on specimens from the Pachycephalosauridae family (the bone-heads), involved the development of computer models derived from CT scans of fossilised skulls in order to map the airflow in and out of a dinosaur’s snout.  Palaeontologists have known for some time that a number of different types of dinosaur had very complex nasal passages.  The nasal region although mostly associated with breathing (respiration), also plays an important role in helping to define and enhance a creature’s sense of smell.  In addition, the ability to bring in air at an ambient temperature into the skull may have a function in helping the brain to keep cool.  In the Late Cretaceous of North America, Pachycephalosaurs may have had small brains in their heavily armoured skulls but they did not want them to cook inside those thick heads.

A Model of a Typical Member of the Pachycephalosauridae Family

Nosing around the nasal passages of dinosaurs.

Nosing around the nasal passages of dinosaurs.

Picture Credit: Everything Dinosaur

Lead author of the research, which has just been published in the academic journal “The Anatomical Record”, Jason Bourke (Ohio University) states:

“Figuring out what’s going on in their [dinosaurs] complicated snouts is challenging because noses have so many different functions.  It doesn’t help that all the delicate soft tissues rotted away millions of years ago.”

In order to gain an appreciation of the nasal passages of long extinct dinosaurs, the team examined the snouts of extant relatives of the Dinosauria, namely birds, crocodiles and other reptiles including lizards.  The study of fossil skulls of Pachycephalosaurs was supported by lots of dissections, blood-vessel injections to map blood flow as well as CT scans.  The researchers also relied upon computer models that provided a three-dimensional analysis of airflow.

A technique more commonly applied to the study of airflow in the aerospace industry, a technique called computational fluid dynamics was used to better understand how extant animals such as Alligators and Ostriches breathe.

As PhD student Jason Bourke explained:

“Once we got a handle on how animals breathe today, the tricky part was finding a good candidate among the dinosaurs to test our methods.”

The team turned to a family of bird-hipped dinosaurs known as the Pachycephalosaurs, the bone-headed dinosaurs.  These particular dinosaurs were chosen as a number of specimens were readily available to study in the United States/Canada and skulls attributed to several genera were known.   The thick skulls with their ornamentation may have been used  by these relatively small dinosaurs for head-butting or visual displays.  The skull bones, some of which are several inches thick, has helped to preserve details of the nasal passages which the scientists were able to map and analyse in great detail.

Getting Up a Dinosaur’s Nose

Airflow in the nasal passages in the Pachycephalosaur Stegosaurus validum is mapped.

Airflow in the nasal passages in the Pachycephalosaur Stegoceras validum is mapped.

Picture Credit: Ohio University/The Anatomical Record

One Pachycephalosaur that was studied was Stegoceras (S. validum) and the researchers were able to show that some of the airflow that they mapped would have carried odours to the olfactory region, helping to improve this dinosaur’s sense of smell.  In addition, the team tried to piece together the shape of the nasal concha, otherwise known as the turbinates, that help to direct and manage airflow through the nasal passage.  This small bone, superficially resembles a sea shell (hence the name) and the fossil evidence supports the presence of such a bone but it is not found in the Dinosauria fossil record (as far as we at Everything Dinosaur know).  As the researchers point out, there is the bony ridge preserved on Pachycephalosaur skulls that indicate its presence and when airflow models were created, the best and most efficient ones produced included a turbinate structure within the model.

Commenting on the research results, Jason Bourke stated:

“We don’t really know what the exact shape of the respiratory turbinate was in Stegoceras, but we know that some kind of baffle had to be there.”

Study co-author Ruger Porter (Ohio University), pointed out that turbinates may well direct air to the olfactory region, but they might have also played another critical role, helping to cool the brain or at least helping to conserve moisture that might have been lost during exhalation.

Porter pointed out:

“The fossil evidence suggests that Stegoceras was basically similar to an Ostrich or an Alligator.  Hot arterial blood from the body was cooled as it passed over the respiratory turbinates and then that cooled venous blood returned to the brain.”

Whether this new research supports the theory that these dinosaurs were warm-blooded (endothermic) is being debated, but it does suggest there was more going on within dinosaur’s noses than scientists had previously thought.  It is hoped that the research team will be able to apply their analytical methods to other types of dinosaur such as the Thyreophora (armoured dinosaurs), known for their notoriously complex nasal passages.  This research may also provide answers to the questions concerning the bizarre shape of many crests found in Lambeosaurine dinosaurs (duck-billed dinosaurs).

19 10, 2014

Lesson Plan – How Do Fossils Form?

By | October 19th, 2014|Key Stage 1/2|Comments Off on Lesson Plan – How Do Fossils Form?

Lesson Plan – How Do Fossils Form?

Everything Dinosaur team members have created this simple lesson plan that can be set up as a  class experiment for part of a science week or term topic exploring rocks and fossils.  Using very basic resources, the process of permineralisation can be demonstrated in a classroom, one of the key factors in petrifaction, the process of fossilisation.  Living things have lots of pores and open spaces in them.  Even hard parts of an organism such as wood, teeth and bones are full of holes.  It is these holes that can become filled with minerals that help in the process of turning organic matter into a fossil.

There are many different types of fossil, trace fossils, natural casts, internal moulds, external moulds and so forth but how to demonstrate to a class the fossilisation process?

Lesson Plan Experiment – Observable Movement of Coloured Water up a Celery Stalk to Prove that Open Spaces in Living Things Can be Permineralised

Resources

  • Celery stalks (with leaves on if possible)
  • Glass or clear plastic beaker
  • Food colouring (just a few drops – blue or red works best)
  • Magnifying glasses for the children to study the celery stalks closely and to observe the change in colour
  • Simple chopping tool to trim the celery stalks
  • Ruler to measure the length of the stalks used
  • Tap water

Resources for the How Fossils Form Experiment

Simple resources required, the class can be split into groups for this experiment.

Simple resources required, the class can be split into groups for this experiment.

Picture Credit: Everything Dinosaur

Divide the class into groups and give each group a set of the above resources.  Explain using pictures of fossils (available free of charge from Everything Dinosaur), what fossils are, stress that many fossils are the remains of once living things that have been turned to stone (petrifaction).  The celery’s vascular transport system can be used to demonstrate that living things are not solid objects but have many open spaces and pores in them.  By placing a stalk of celery into coloured water and observing the change in colour, this experiment demonstrates this principle very nicely.  The ruler can be used to measure the length of the stalks, and the magnifying glasses can assist with the children’s observation of the structure of the plant and the movement of the coloured dye via the xylem.

Overnight Dramatic Changes Can Be Seen

Overnight the food colouring can be clearly seen.

Overnight the food colouring can be clearly seen.

Picture Credit: Everything Dinosaur

The children can record what they observe during the course of the day and the experiment can be left overnight or even for longer if required.

For more detailed information about this lesson and for further information about fossil formation: How Do Fossils Form?

A Close up of a Dinosaur Bone Shows the Internal Structure

The internal structure of bone can be clearly seen (Haversian canals etc).

The internal structure of bone can be clearly seen (Haversian canals etc).

Picture Credit: Everything Dinosaur

Extension Ideas

  1. Why was it easier to see the colour change in the leaves and not the stalks?  Hint – links to the functions of different parts of the plant
  2. What happens to the softer parts of animals?  Do they fossilise?
  3. What examples of fossils formed from the soft parts of animals and plants can the students find?  More able pupils can be asked to work out what conditions are needed for soft parts to turn to fossils.
  4. Can the class think up examples of other types of fossil – footprints, fossils of shells, fossilised wood etc?

By keeping a record of this experiment it will work in nicely when it comes to exploring the roles of different parts of the plant.

National Curriculum (England) Coverage

Plants (Years 1, 2 and 3) with links onward to KS3
Living Things and their Habitats (Years 2, 4, 5 and 6)
Rocks and Fossils (Year 3)
Animals including Humans (Years 1-6)
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