Dominican amber differentiates itself from Baltic amber by being mostly transparent and often containing a higher number of fossil inclusions.

Others have interpreted the fossil bearing rocks along Red Deer River in Alberta, Canada, as supporting a gradual extinction of non-avian dinosaurs ; during the last 10 million years of the Cretaceous layers there, the number of dinosaur species seems to have decreased from about 45 to about 12.

Paleontologist Donald Prothero noted that this is illustrated by the fact that the number of species known through the fossil record is less than 5 % of the number of known living species, suggesting that the number of species known through fossils must be far less than 1 % of all the species that have ever lived.

The groups considered to have a good fossil record, including a number of transitional fossils between traditional groups, are the vertebrates, the echinoderms, the brachiopods and some groups of arthropods.

The total number of fossil felids that are known to science is low compared to other carnivoran families such as dogs and bears.

It is the sole living representative of its family ( Ornithorhynchidae ) and genus ( Ornithorhynchus ), though a number of related species have been found in the fossil record.

Mary Anning ( 21 May 1799 – 9 March 1847 ) was a British fossil collector, dealer, and paleontologist who became known around the world for a number of important finds she made in the Jurassic marine fossil beds at Lyme Regis in Dorset, where she lived.

Facies can be distinguished in a number of ways: the most common ways are by the lithology ( for example: limestone, siltstone or sandstone ) or by fossil content.

In the second half of the 20th century, a number of fossil forms have been found in Proterozoic rocks, but the upper boundary of the Proterozoic has remained fixed at the base of the Cambrian, which is currently placed at 542 Ma.

The family has one surviving species, the Dugong ( Dugong dugon ), one recently extinct species, the Steller's Sea Cow ( Hydrodamalis gigas ), and a number of extinct genera known from the fossil record.

While it is one of the most profound evolutionary changes known, it is also one of the best understood, largely thanks to a number of amazing fossil finds in the late 20th century combined with improved phylogenetic analysis.

Genetic divergence of mangrove lineages from terrestrial relatives, in combination with fossil evidence, suggests mangrove diversity is limited by evolutionary transition into the stressful marine environment, and the number of mangrove lineages has increased steadily over the Tertiary with little global extinction.

The Hagerman Horse Quarry fossil beds have produced 20 complete skeletons and a number of partial skeletons of this zebra-like ancestor of today ’ s horse.

A number of local companies maintain fossil dig areas where they allow visitors to dig their own fossils for a small fee.

Arkarua is a small, Precambrian disk-like fossil with a raised center, a number of radial ridges on the rim, and a five-pointed central depression marked with radial lines of 5 small dots from the middle of the disk center.

The number of prehistoric ( fossil ) species of gastropods is at least 15, 000 species.

Also included were a number of paleontologists like Edward Drinker Cope and Alpheus Hyatt who felt that the fossil record showed orderly, almost linear, patterns of development that they felt were better explained by Lamarckian mechanisms than by natural selection.

Hydrogen vehicles are one of a number of proposed alternatives to the modern fossil fuel powered vehicle infrastructure.

A number of fossil species have been discovered, mainly in North America.

Despite the existence of a fossil record, full classification and phylogeny of the sturgeon species has been difficult to determine, in part due to the high individual and ontogenic variation, including geographical clines in certain features, such as rostrum shape, number of scutes and body length.

Only a very small number of fossil specimens are known, the oldest dating back to the Pleistocene, and no fossils belonging to other species from the same family have yet been discovered.

Although the United States and the U.S.S.R. have been arguing whether there shall be four, five or six top assistants, the most important element in the situation is not the number of deputies but the manner in which these deputies are to do their work.

Hence all teachers, good and bad, who have been teaching for a given number of years are paid the same salary.

To have any success in this effort, we must ourselves view it as an enterprise stretching over a considerable number of years, and we must encourage the recipients of our aid to view it in the same fashion.

For those communities which have financial difficulties in effecting adjustments, there are a number of alternatives any one of which alone, or in combination with others, would minimize if not even eliminate the problem.

There have been a number of sound plans proposed.

Thus, in the last few years, a number of programs which looked very promising at the time their development was commenced have since been completely eliminated.

To provide the continuous flow of information basic to administrative decisions, a number of institutions have established offices of institutional research.

A large number of these Juniors have 7 and 8 wins to their credit and are seasoned campaigners.

As America on wheels was responsible for an industry of motor courts, motels, and drive-in establishments where you can dine, see a movie, shop, or make a bank deposit, the ever-increasing number of boating enthusiasts have sparked industries designed especially to accommodate them.

Aside from the Ruger carbine, a number of hunting rifles have been introduced for the first time.

A number of them must have fallen into disfavor ; ;

Based on this phenomenon, a number of investigators have used this method to `` look through '' human organs.

In the GE plan, a number of individual contributors have positions and compensation higher than those of many managers.

`` These recent steps do not offer the possibility of extension to the great number of senior engineers who have displayed technical competence.

The railroads have responded by adding 20,000 more box cars with doors 12' or wider for forklift unloading ( a 21% increase while the total number of box cars was falling 6% ) and by cutting their freight rates twice on lumber shipped in heavily loaded cars.

However, whether you arrange to have a European or American model, if you rent a car with the proper seating capacity in relation to the number of people in your party, your transportation expense will average very close to $10.00 per day per passenger.

For the last two years, this frontier of the arts has produced a number of so-called `` non-dramas '' which have left indelible, bittersweet impressions on the psyche of this veteran theatregoer.

A number of semiempirical estimates by various workers lead to the conclusion that the Af bond becomes symmetric when the Af bond length is about 2.4 to 2.5 A, but aside from the possible example of nickel dimethylglyoxime there have been no convincing reports of symmetric Af bonds.

Since practical washing procedures are both lengthy and expensive, a number of laboratory tests have been developed for the numerical evaluation of detergents.

For an experiment to qualify as a binomial experiment, it must have four properties: ( 1 ) there must be a fixed number of trials, ( 2 ) each trial must result in a `` success '' or a `` failure '' ( a binomial trial ), ( 3 ) all trials must have identical probabilities of success, ( 4 ) the trials must be independent of each other.

The graph, as a set, may have a finite number of components.

Furthermore, one can find a neighborhood of Q in which the difference function is monotone, for since it is analytic it can have only a finite number of extrema in any interval.

The remaining ( incomplete ) components all have an even number of ordinary points at any argument, and are defined only on a proper sub-interval of Aj.

A number of strong independent agencies, established in some cases with governmental or royal support, have conducted large medical, social, educational and research operations in particular parts of the Congo and Ruanda-Urundi.