Sentence examples for by the first occurrence from inspiring English sources

The base of each zone is defined by the first occurrence of the taxon.

This pattern is also matched by the first occurrence of dinosaurs in the Germanic Basin32, within the Ansbacher Sandstein (Stuttgart Formation, upper Schilfsandstein), which correlate with the Heiligkreuz Formation and represent the regional expression of the CPE.

The boundary point, or "golden spike," is marked by the base of the graptolite biozone of Parakidograptus acuminatus fixed by the first occurrence of that species together with the graptolite Akidograptus ascensus.

By international agreement, the base of the Pridoli Series is defined by the first occurrence of the graptolite species Monograptus parultimus in rock exposures at the entrance to the Pozary Quarries, which lie about 1.5 km (about 1 mile) east of Reporyje, outside of southwestern Prague.

In the Queen Charlotte Islands, the radiolarian turnover is also followed by the last occurrence of conodont Norigondolella sp. and Triassic ammonoid Choristoceras rhaeticum, and predated by the first occurrence of Jurassic ammonoid Psiloceras aff.

Slow wave sleep (SWS) was determined as the sum of time spent in sleep stages 3 and 4. Latencies to SWS and REM sleep refer to time from the sleep onset, defined by the first occurrence of sleep sage 1 followed by sleep stage 2. Intervals during acute stimulation were not scored due to the excessive signal artifacts.

(I have emphasized the point by putting the first occurrence in italics and the second in bold).

By contrast, the first occurrence of boninites, which required a source of volatiles, certainly marks the subduction of a hydrated lithosphere.

We deduced the timing of each node in our tree by identifying the first occurrence for each of the terminal taxa in our study as well as for larger clades containing one or more of these taxa.

Diabetes cases were identified from the RAI-MDS data by searching for the first occurrence of a diabetes diagnosis in admission and annual assessments between April 1, 2005 and March 31 , 2011

The onset of septic shock was defined by the time of the first occurrence of recurrent or persistent hypotension (systolic blood pressure <90 mmHg or mean blood pressure <65 mmHg) despite adequate fluid loading (i.e., at least 30 mL/kg) [24].